PART II

PRINCIPLES OF INCEPTION

13. _Illustrative Secondary Processes_

In this part of the work, an attempt will be made to place before the

reader some of the purely terrestrial and other evidential phenomena on

which the conclusions of the preceding General Statement are founded.

The complete and absolute verification of that Statement is obviously

beyond experimental device. Bound, as we are, within the confines of one

planet, and unable to communicate with the others, we can have no direct

experimental acquaintance with really separate bodies (Sec. 5) in space.

But, if from purely terrestrial experience we can have no direct proofs

on such matters, we have strong evidential conclusions which cannot be

gainsayed. If the same kind of energy operates throughout the solar

system, the experimental knowledge of its properties gained in one field

of research is valuable, and may be readily utilised in another. The

phenomena which are available to us for study are, of course, simply the

ordinary energy processes of the earth--those operations which in the

foregoing Statement have been described as secondary energy processes.

Their variety is infinite, and the author has accordingly selected

merely a few typical examples to illustrate the salient points of the

scheme. The energy acting in these secondary processes is, in every

case, derived, either directly or indirectly, from the energy of

rotation or axial energy of the earth. In themselves, the processes may

be either energy transformations or energy transmissions or a

combination of both these operations. When the action involves the

bodily movement of material mass in space, the dynamical energy thus

manifested, and which may be transmitted by the movement of this

material, is termed mechanical or "work" energy (Sec. 31); when the energy

active in the process is manifested as heat, chemical, or electrical

energy, we apply to it the term "molecular" energy. The significance of

these terms is readily seen. The operation of mechanical or "work"

energy on a mass of material may readily proceed without any permanent

alteration in the internal arrangement or general structure of that

mass. Mechanical or "work" energy is dissociated from any molecular

action. On the other hand, the application of such forms of energy as

heat or electrical energy to material leads to distinctly molecular or

internal effects, in which some alteration in the constitution of the

body affected may ensue. Hence the use of the terms, which of course is

completely arbitrary.

The principal object of this part of the work is to illustrate clearly

the general nature, the working, and the limits of secondary processes.

For this purpose, the author has found it best to refer to certain more

or less mechanical contrivances. The apparatus made use of is merely

that utilised in everyday work for experimental or other useful

purposes. It is essentially of a very simple nature; no originality is

claimed for it, and no apology is offered for the apparent simplicity of

the particular energy operations chosen for discussion. In fact, this

feature has rather led to their selection. In scientific circles to-day,

familiarity with the more common instances of energy operations is apt

to engender the belief that these processes are completely understood.

There is no greater fallacy. In many cases, no doubt, the superficial

phenomena are well known, but in even the simplest instances the

mechanism or ultimate nature of the process remains unknown. A free and

somewhat loose method of applying scientific terms is frequently the

cloak which hides the ignorance of the observer. No attempt will here be

made to go beyond the simple phenomena. The object in view is simply to

describe such phenomena, to emphasise and explain certain aspects of

already well-known facts, which, up to the present, have been neglected.

In some of the operations now to be described, mechanical or "work"

energy is the active agent, and material masses are thereby caused to

execute various movements in the lines or field of restraining

influences. For ordinary experimental convenience, the material thus

moved must of necessity be matter in the solid form. The illustrative

value of our experimental devices, however, will be very distinctly

improved if it be borne in mind that the operations of mechanical energy

are not restricted to solids only, but that the various processes of

transformation and transmission here illustrated by the motions of solid

bodies may, in other circumstances, be carried out in a precisely

similar fashion by the movements of liquids or even of gases. The

restrictions imposed in the method of illustration are simply those due

to the limitations of human experimental contrivance. Natural operations

exhibit apparatus of a different type. By the movements of solid

materials a convenient means of illustration is provided, but it is to

be emphasised that, so far as the operations of mechanical energy are

concerned, the precise form or nature of the material moved, whether it

be solid, liquid, or gaseous, is of no consequence. To raise one pound

of lead through a given distance against the gravitative attraction of

the earth requires no greater expenditure of energy than to raise one

pound of hydrogen gas through the same distance. The same principle

holds in all operations involving mechanical energy.

Another point of some importance which will be revealed by the study of

secondary operations is that every energy process has in some manner

definite energy limits imposed upon it. In the workings of mechanical or

"work" energy it is the mass value of the moving material which, in this

respect, is important. The mass, in fact, is the real governing factor

of the whole process (Sec. 20). It determines the maximum amount of energy

which can be applied to the material, and thus controls the extent of

the energy operation.

But in actions involving the molecular energies, the operation may be

limited by other considerations altogether. For example, the application

of heat to a solid body gives rise to certain energy processes (Sec. 27).

These processes may proceed to a certain degree with increase of

temperature, but a point will finally be attained where change of state

of the heated material takes place. This is the limiting point of this

particular operation. When change of state occurs, the phenomena will

assume an entirely different aspect. The first set of energy processes

will now be replaced by a set of operations absolutely different in

nature, themselves limited in extent, but by entirely different causes.

The first operation must thus terminate when the new order appears. In

this manner each process in which the applied energy is worked will be

confined within certain limiting boundaries. In any chain of energy

operations each link will thus have, as it were, a definite length. In

chemical reactions, the limits may be imposed in various ways according

to the precise nature of the action. Chemical combination, and chemical

disruption, must be looked on as operations which involve not only the

transformation of energy but also the transformation of matter. In most

cases, chemical reactions result in the appearance of matter in an

entirely new form--in the appearance, in fact, of actually different

material, with physical and energy properties absolutely distinct from

those of the reacting constituents. This appearance of matter in the new

form is usually the evidence of the termination, not only of the

particular chemical process, but also of the energy process associated

with it. Transformation of energy may thus be limited by transformation

of matter.

Examples of the limiting features of energy operations could readily be

multiplied. Even a cursory examination of most natural operations will

reveal the existence of such limits. In no case do we find in Nature any

body, or any energy system, to which energy may be applied in unlimited

amount, but in every case, rigid energy limits are imposed, and, if

these limits are exceeded, the whole energy character of the body or

system is completely changed.

14. _Incepting Energy Influences_

In experimental and in physical work generally, it has been customary,

in describing any simple process of energy transformation, to take

account only of those energies or those forms of energy which play an

active part in the process--the energy in its initial or applied form

and the energy in its transformed or final form. This method, however,

requires enlarging so as to include another feature of energy

transformation, a feature hitherto completely overlooked, namely, that

of incepting energy. Now, this conception of incepting energy, or of

energy as an incepting influence, is of such vital importance to the

author's scheme, that it is necessary here, at the very outset, to deal

with it in some detail. To obtain some idea of the general nature of

these influences, it will be necessary to describe and review a few

simple instances of energy transformation. One of the most illuminating

for this purpose is perhaps the familiar process of dynamo-electric

transformation.

A spherical mass A (Fig. 1) of copper is caused to rotate about its

central axis in the magnetic field in the neighbourhood of a long and

powerful electro-magnet. In such circumstances, certain well-known

transformations of energy will take place. The energy transformed is

that dynamical or "work" energy which is being applied to the spherical

mass by the external prime mover causing it to rotate. As a result of

this motion in the magnetic field, an electrical action takes place;

eddy currents are generated in the spherical mass, and the energy

originally applied is, through the medium of the electrical process,

finally converted into heat and other energy forms. The external

evidence of the process will be the rise in temperature and

corresponding expansion of the rotating mass.

[Illustration: FIG. 1]

Such is the energy transformation. Let us now review the conditions

under which it takes place. Passing over the features of the "work"

energy applied and the energy produced in the transformation, it is

evident that the primary and essential condition of the whole process is

the presence of the magnetic field. In the absence of this influence,

every other condition of this particular energy operation might have

been fulfilled without result. The magnetic field is, in reality, the

determining agency of the process. But this field of magnetic force is

itself an energy influence. Its existence implies the presence of

energy; it is the external manifestation of that energy (usually

described as stored in the field) which is returned, as shown by the

spark, when the exciting circuit of the electro-magnet is broken. The

transformation of the dynamical or "work" energy (Sec. 31) applied to the

rotating sphere is thus carried out by the direct agency, under the

power, or within the field of this magnetic energy influence, to which,

accordingly, we apply the expression, incepting energy influence, or

incepting energy.

There are several points to be noted with regard to these phenomena of

inception. In the first place, it is clear that the energy which thus

constitutes the magnetic field plays no active part in the main process

of transformation: during the operation it neither varies in value nor

in nature: it is entirely a passive agent. Neither is any continuous

expenditure of energy required for the maintenance of this incepting

influence. It is true that the magnetic field is primarily due to a

circulatory current in the coils or winding of the electro-magnet, but

after the initial expenditure of energy in establishing that field is

incurred, the continuous expenditure of energy during the flow of the

current is devoted to simply heating the coils. A continuous heat

transformation is thus in progress. The magnetic energy influence,

although closely associated with this heat transformation, yet

represents in itself a distinct and separate energy feature. This last

point is, perhaps, made more clear if it be assumed that, without

altering the system in any way, the electro-magnet is replaced by a

permanent magnet of precisely the same dimensions and magnetic power.

There would then be no energy expenditure whatever for excitation, but

nevertheless, the main transformation would take place in precisely the

same manner and to exactly the same degree as before. The incepting

energy influence is found in the residual magnetism.

If an iron ball or sphere were substituted, in the experiment, for the

copper one, the phenomena observed on its rotation would be of an

exactly similar nature to those described above. There is, however, one

point of difference. Since the iron is magnetic, the magnet pole will

now exert an attractive force on the iron mass, and if the latter were

in close proximity to the pole (Fig. 1), a considerable expenditure of

energy might be required to separate the two. It is evident, then, that

in the case of iron and the magnetic metals, this magnetic influence is

such that an expenditure of energy is required, not only to cause these

materials to move in rotation so as to cut the lines of the field of the

magnetic influence, but also to cause them to move outwards from the

seat of the influence _along_ the lines of the field. The movements,

indeed, involve transformations of energy totally different in nature.

Assuming the energy to be obtained, in both cases, from the same

external source, it is, in the first instance, converted by rotatory

motion in the field into electrical and heat energy, whereas, in the

second case, by the outward motion of displacement from the pole, it is

transformed and associated with the mass in the form of energy of

position or energy of displacement relative to the pole. Since the

attractive force between the iron mass and the pole may be assumed to

diminish according to a well-known law, the energy transformation per

unit displacement will also diminish at the same rate. The precise

nature and extent of the influence of the incepting agent thus depend on

the essential qualities of the energised material under its power. In

this case, the magnetic metals, such as iron, provide phenomena of

attraction which are notably absent in the case of the dia-magnetic

metals such as copper. Other substances, such as wood, appear to be

absolutely unaffected by any movement in the magnetic field. The precise

energy condition of the materials in the field of the incepting

influence is also an important point. The incepting energy might be

regarded as acting, not on the material itself, but rather on the energy

associated with that material. From the phenomena already considered, it

is clear that before the incepting influence of magnetism can act on the

copper ball, the latter must be endowed with energy of rotation. It is

on this energy, then, that the incepting influence exerts its

transforming power. It would be useless to energise the copper ball, say

by raising it to a high temperature, and then place it at rest in the

magnetic field; the magnetic energy influence would not operate on the

heat energy, and consequently, no transformation would ensue.

It is easy to conceive, also, that in the course of an energy

transformation, the material may attain an energy condition in which the

incepting influence no longer affects it. Take once more the case of the

iron ball. It is well known that, at a high temperature, iron becomes

non-magnetic. It would follow, then, that if the rotational

transformation in the magnetic field could be carried out to the

requisite degree, so that, by the continuous application of that heat

energy which is the final product of the process, the ball had attained

this temperature, then the other transformation consequent on the

displacement of the ball from the attracting pole could not take place.

No change has really occurred in the incepting energy conditions. They

are still continuous and persistent, but the energy changes in the

material itself have carried it, to a certain degree, beyond the

influence of these conditions.

15. _Cohesion as an Incepting Influence_

Other aspects of incepting energy may be derived from the examples cited

above. Returning to the case of the rotating copper sphere, let it be

assumed that in consequence of its rotation in the magnetic field it is

raised from a low to a high temperature. Due to the heating effect

alone, the mass will expand or increase in volume. This increase is the

evidence of a definite energy process by which certain particles or

portions of the mass have in distortion gained energy of

position--energy of separation--or potential energy relative to the

centre of the sphere. In fact, if the mass were allowed to cool back to

its normal condition, this energy might by a suitable arrangement be

made available for some form of external work. It is obvious, however,

that this new energy of position or separation which has accrued to the

mass in its heated condition has in reality been obtained by the

transformation of the "work" energy originally applied. The abnormal

displacement of certain particles or portions of the mass from the

centre of the sphere is simply the external evidence of their increased

energy. Now this displacement, or strain, due to the heat expansion, is

carried out against the action of certain cohesive forces or stresses

existing between the particles throughout the mass. These cohesive

forces are, in fact, the agency which determines this transformation of

heat into energy of position. Their existence is essential to the

process. But these cohesive forces are simply the external manifestation

of that energy by virtue of which the mass tends to maintain its

coherent form. They are the symbol of that energy which might be termed

the cohesion energy of the mass--they are, in fact, the symbol of the

incepting energy influence of the transformation. This incepting energy

influence of cohesion is one which holds sway throughout all solid

material. It is, therefore, found in action in every movement involving

the internal displacement or distortion of matter. It is a property of

matter, and accordingly it is found to vary not only with the material,

but also with the precise physical condition or the energy state of the

material with which it is associated. In this respect, it differs

entirely from the preceding magnetic influence. The latter, we have

seen, has no direct association with the copper ball, or with the

material which is the actual venue of the transformation. As an energy

influence, it is itself persistent, and unaffected by the energy state

of that material. On the other hand, the cohesion energy, being purely a

property of the material which is the habitat of the energy process, is

directly affected by its energy state. This point will be clearer by

reference to the actual phenomena of the heat transformation. As the

process proceeds, the temperature of the mass as the expansion increases

will rise higher and higher, until, at a certain point, the solid

material is so energised that change of state ensues. At this, the

melting-point of the material, liquefaction takes place, and its

cohesive properties almost vanish. In this fashion, then, a limit is

clearly imposed on the process of heat transformation in the solid

body--a limit defined by the cohesive or physical properties of the

particular material. In this limiting power lies the difference between

cohesion and magnetism as incepting influences. Looking at the whole

dynamo-electric transformation in a general way, it will be clear that

the magnetic influence in no way limits or affects the amount of

dynamical or "work" energy which may be applied to the rotating sphere.

This amount is limited simply by the cohesive properties of the material

mass in rotation. The magnetic influence might, in fact, be regarded as

the primary or inducing factor in the system, and the cohesion influence

as the secondary or limiting factor.

16. _Terrestrial Gravitation as an Incepting Influence_

The attractive influence of gravitation appears as an incepting agency

in terrestrial as well as in celestial phenomena. In fact, of all the

agencies which incept energy transformations on the earth, gravitation,

in one form or another, is the most universal and the most important.

Gravitation being a property of all matter, no mundane body, animate or

inanimate, is exempt from its all-pervading influence, and every

movement of energised matter within the field of that influence leads

inevitably to energy transformation.

Let us take a concrete illustration. A block of solid material is

supported on a horizontal table. By means of a cord attached, energy is

applied to the block from an external source, so that it slides over the

surface of the table. As a result of this motion and the associated

frictional process, heat energy will make its appearance at the sliding

surfaces of contact. This heat energy is obviously obtained by the

transformation of that energy originally applied to the block from the

external source. What is the incepting influence in this process of

transformation? The incepting influence is clearly the gravitative

attraction of the earth operating between the moving block and the

table. The frictional process, it is well known, is dependent in extent

or degree on the pressure between the surfaces in contact. This pressure

is, of course, due to the gravitative attraction of the earth on the

mass of the block. If it be removed, say by supporting the block from

above, the heat-transformation process at the surfaces at once

terminates. Gravity, then, is the primary incepting influence of the

process. The effect of gravitation in transformation has apparently been

eliminated by supporting the block from above and removing the pressure

between block and table. It is not really so, however, because the

pressure due to the gravitative attraction of the earth on the block has

in reality only been transferred to this new point of support, and if a

movement of the block is carried out it will be found that the heat

transformation has been also transferred to that point. But there are

also other influences at work in the process. The extent of the heat

transformation depends, not only on the pressure, but also on the nature

of the surfaces in contact. It is evident, that in the sliding movement

the materials in the neighbourhood of the surfaces in contact will be

more or less strained or distorted. This distortion is carried out in

the lines of the cohesive forces of the materials, and is the real

mechanism of the transformation of the applied work energy into heat. It

is obvious that the nature of the surfaces in contact must influence the

degree of distortion, that is, whether they are rough or smooth; the

cohesive qualities of the materials in contact will depend also on the

nature of these materials, and the extent of the heat transformation

will be limited by these cohesive properties in precisely the same way

as described for other examples (Sec. 15). The function of gravitation in

this transformation is, obviously, again quite passive in nature, and is

in no way influenced by the extent of the process. Gravitation is, as it

were, only the agency whereby the acting energy is brought into

communication with the cohesive forces of the sliding materials.

A little reflection will convey to the reader the vast extent of this

influence of gravitation in frictional phenomena, and the important

place occupied by such phenomena in the economy of Nature. From the

leaf which falls from the tree to the mighty tidal motions of air,

earth, and sea due to the gravitative effects of the sun and moon, all

movements of terrestrial material are alike subject to the influence of

terrestrial gravitation, and will give rise to corresponding heat

processes. These heat processes are continually in evidence in natural

phenomena; the effect of their action is seen alike on the earth's

surface and in its interior (internal heating). Of the energy operating

in them we do not propose to say anything further at this stage, except

that it is largely communicated to the atmospheric air masses.

17. _The Gravitation Field_

The foregoing examples of transformation serve to place before the

reader some idea of the general nature and function of an incepting

energy influence. But for the broadest aspects of the latter agencies it

is necessary to revert once more to celestial phenomena. As already

indicated in the General Statement, the primary transformations of

planetary axial energy are stimulated by certain agencies inherent to,

and arising from, the central mass of the system. These energy agencies

or effects operate through space, and are entirely passive in nature.

They are in no way associated with energy transmission; they are merely

the determining causes of the energy-transforming processes which they

induce, and do not in the least affect the conservative energy

properties of the planetary masses over which their influence is cast.

Of the precise number and nature of such influences thus exerted by the

primary mass we can say nothing. The energy transformations which are

the direct result of their action are so extensive and so varied in

character that we would hesitate to place any limit on the number of the

influences at work. Some of these influences, however, being associated

with the phenomena of everyday experience, are more readily detected in

action than others and more accessible to study. It is to these that we

naturally turn in order to gain general ideas for application to more

obscure cases.

Of the many incepting influences, therefore, which may emanate from the

primary mass there are three only which will be dealt with here. Each

exerts a profound action on the planetary system, and each may be

readily studied and its working verified by the observation of common

phenomena. These influences are respectively the gravitation, the

thermal, and the luminous fields.

The general nature and properties of the gravitation field have to some

extent been already foreshadowed (Secs. 4, 6, 16). Other examples will be

dealt with later, and it is unnecessary to go into further detail here.

The different aspects, however, in which the influence has been

presented may be pointed out. Firstly, in the separate body in space, as

an inherent property of matter (Sec. 2); secondly, as an attractive

influence exerted across space between primary and planet, both

absolutely separate bodies (Sec. 5); and thirdly, as a purely planetary or

secondary incepting influence (Sec. 16). In every case alike we find its

function to be of an entirely passive nature. Its most powerful effect

on planetary material is perhaps manifested in the tidal actions (Sec. 9).

With respect to these movements, it may be pointed out that the

planetary material periodically raised from the surface is itself

elevated against the inherent planetary gravitative forces, and also, to

a certain extent, against the cohesive forces of planetary material.

Each of these resisting influences functions as an incepting agency, and

thus the elevation of the mass involves a transformation of energy (Sec.

4). The source of the energy thus transformed is the axial energy of the

planet, and the new forms in which it is manifested are energy of

position or potential energy relative to the planetary surface, and heat

energy. On the return of the material to its normal position, its energy

of position, due to its elevation, will be returned in its original form

of axial energy. In the case of the heat transformation, however, it is

to be noted that this process will take place both as the material is

elevated and also as it sinks once more to its normal position. The

heat transformation thus operates continuously throughout the entire

movement. The upraising of the material in the tidal action is brought

about entirely at the expense of inherent planetary axial energy. The

gravitative and cohesive properties of the planetary material make such

a transformation process possible. It is in virtue of these properties

that energy may be applied to or expended on the material in this way.

The tidal action on the planetary surface is, in fact, simply a huge

secondary process in which axial energy is converted into heat. The

primary incepting power is clearly gravitation.

Of the aspect of gravitation as a purely planetary influence (Sec. 16)

little requires to be said. The phenomena are so prominent and familiar

that the reader may be left to multiply instances for himself.

18. _The Thermal Field_

The thermal field which is induced by and emanates from the primary mass

differs from the gravitation field in that, so far as we know, it is

unaccompanied by any manifestation of force, attractive or otherwise.

Its action on the rotating planetary mass may be compared to that of the

electro-magnet on the rotating copper sphere (Sec. 14); the electro-magnet

exerts no force on the sphere, but an energy expenditure is,

nevertheless, required to rotate the latter through the field of the

magnetic influence.

To this thermal field, then, in which the planets rotate, we ascribe all

primary planetary heating phenomena. The mode of action of the thermal

field appears to be similar to that of other incepting influences. By

its agency the energy of axial rotation of planetary material is

directly converted into the heat form. As already shown (Sec. 17), heat

energy may be developed in planetary material as a result of the action

of other incepting agencies, such as gravitation. These processes are,

however, more or less indirect in nature. But the operation due to the

thermal field is a direct one. The heat energy is derived from the

direct transformation of planetary axial energy of rotation without

passing through any intermediate forms. In common parlance, the thermal

field is the agency whereby the primary mass heats the planetary system.

No idea of transmission, however, is here implied in such phraseology;

the heating effect produced on any planetary mass is entirely the result

of the transformation of its own energy; the thermal field is purely and

simply the incepting influence of the process. Now, in virtue of the

configuration of the rotating planetary masses, their material in

equatorial regions is much more highly energised than the material in

the neighbourhood of the poles, and will, accordingly, move with much

greater linear velocity through the thermal field. The heat

transformation will vary accordingly. It will be much more pronounced at

the equator than at the poles, and a wide difference in temperature will

be maintained between the two regions. The thermal field, also, does not

necessarily produce the same heating effect on all planetary material

alike. Some materials appear to be peculiarly susceptible--others much

less so. This we may verify from terrestrial experience. Investigation

shows the opaque substances to be generally most susceptible, and the

transparent materials, such as glass, rock-salt, tourmaline, &c. almost

insusceptible, to the heating effect of the sun. The influence of the

thermal field can, in fact, operate through the latter materials. A

still more striking and important phenomenon may be observed in the

varying action of the thermal field on matter in its different forms. It

has been already pointed out that, in the course of transformation in

the field of an incepting influence, a material may attain a certain

energy state in which it is no longer susceptible to that influence.

This has been exemplified in the case of the iron ball (Sec. 14) and a

phenomenon of the same general nature is revealed in the celestial

transformation. A piece of solid material of low melting-point is

brought from the polar regions of the earth to the equator. Due to the

more rapid movement across the sun's thermal field, and the consequent

increased action of that field, a transformation of the axial energy of

rotation of the body takes place, whereby it is heated and finally

liquefied. In the liquid state the material is still susceptible to the

thermal field, and the transformation process accordingly proceeds until

the material finally assumes the gaseous form. At this point, however,

it is found that the operation is suspended; the material, in assuming

the gaseous state, has now attained a condition (Sec. 15) in which the

thermal field has no further incepting or transforming influence upon

it. No transformation of its axial energy into the heat form is now

possible by this means; indeed, so far as the _direct_ heating effect of

the sun is concerned, the free gaseous material on the planetary surface

is entirely unaffected. All the evidence of Nature points to the

conclusion that all gaseous material is absolutely transparent to the

_direct_ thermal influence of the sun. Matter in the gaseous form

reaches, as it were, an ultimate or limiting condition in this respect.

This fact, that energised material in the gaseous form is not

susceptible to the thermal field, is of very great importance in the

general economy of Nature. It is, in reality, the means whereby the

great primary process of the transformation of the axial energy of the

earth into the heat form is limited in extent. As will be explained

later, it is the device whereby the planetary energy stability is

conserved. It will be apparent, of course, that heat energy may be

readily applied to gaseous masses by other means, such as conduction or

radiation from purely terrestrial sources. The point which we wish here

to emphasise is, simply, that gaseous material endowed with axial energy

on the planetary surface cannot have this axial energy directly

transformed into heat through the instrumentality of the thermal field

of the primary.

19. _The Luminous Field_

The planetary bodies are indebted to the primary mass not only for heat

phenomena, but also for the phenomena of light. These light phenomena

are due to a separate and distinct energy influence (or influences)

which we term the luminous field.

The mode of action of the luminous field is similar to that of other

incepting influences. It operates from the primary, and is entirely

passive in nature. Like the thermal field, it does not appear to be

accompanied by any manifestation of physical stress or force, except,

indeed, the experimental demonstrations of the "pressure of light" can

be regarded as such. In any case, this in no way affects the general

action of light as an incepting agency. Its action on energised

planetary material gives rise to certain transformations of energy,

transformations exclusive and peculiar to its own influence. We will

refer to terrestrial phenomena for illustrations of its working.

Perhaps the commonest example of transformation in which the luminous

field appears as the incepting agency is seen in the growth of plant

life on the surface of the earth. The growth and development of

vegetation and plants generally is the outward evidence of certain

energy transformations. The processes of growth, however, are of such a

complex nature that it is impossible to state the governing energy

conditions in their entirety, but, considering them merely in general

fashion, it may be said that energy in various forms (potential,

chemical, &c.) is stored in the tissues of the growing material. Now the

source of this energy is the axial energy of the earth, and, as stated

above, the luminous field is an incepting factor (there may be others)

in the process of transformation, a factor whereby this axial energy is

converted into certain new forms. It is well known that, amongst the

factors which influence the growth of vegetation, one of the most potent

is that of light. The presence of sunlight is one of the essential

conditions for the successful working of certain transformations of

plant life, and these transformations vary not only in degree but in

nature, according to the variation of the imposed light in intensity and

quality. Some of the processes of growth are no doubt chemical in

nature. Here, again, light may be readily conceived to have a direct

determining influence upon them, exactly as in the cases of its

well-known action in chemical phenomena--for instance, as in

photography. Other examples will readily occur to the reader. One of the

most interesting is the action of light on the eye itself. It may be

pointed out indeed that light is, first and foremost, a phenomenon of

vision. Whatever may be its intrinsic nature, it is primarily an

influence affecting the eye. But the action of seeing, like all other

forms of human activity, involves a certain expenditure of bodily

energy. This energy is, of course, primarily derived from the axial

energy of the earth through the medium of plant and animal life and the

physico-chemical processes of the body itself. Its presence in one form

or another is, in fact, essential to all the phenomena of life. The

action of seeing accordingly involves the transformation of a certain

modicum of this energy, and the influence which incepts this

transformation is the luminous field which originates in and emanates

from the central mass of the system, the sun. In a similar way,

planetary material under certain conditions may become the source of an

incepting luminous field. It is this light influence or luminous field

which, in common parlance, is said to enter the eye. In that organ,

then, is found the mechanism or machine (Sec. 30), a complicated one, no

doubt, whereby this process of transformation is carried out which makes

the light influence perceptible to the senses. Of the precise nature of

the action little can be said. The theme is rather one for a treatise on

physiology. It may be pointed out, however, with regard to the process

of transformation, that Dewar has already demonstrated the fact that

when light falls on the retina of the eye, an electric current is set up

in the optic nerve. The energy associated with this current is, of

course, obtained at the expense of the bodily energy of the observer,

and this energy, after passing, it may be, through a large number of

transformation processes, will finally be returned to the source from

which it was originally derived, namely, the axial energy of the earth.

The luminous field, also, like the thermal field, has no transforming

effect whatever on the energy of certain substances. It may pass

completely through some and be reflected by others without any sign of

energy transformation. Its properties are, in fact, simply the

properties of light, and must be accepted simply as phenomena. Now, it

is very important, in studying matters of this kind, to realise that it

is impossible ever to get beyond or behind phenomena. It may be pointed

out that in no sphere of physics has the influence of so-called

explanatory mechanical hypotheses been stronger than in that dealing

with the properties of light. New theories are being expounded almost

daily in attempts to explain or dissect simple phenomena. But it may be

asked, In what does our really useful knowledge of light consist?

Simply in our knowledge of phenomena. Beyond this, one cannot go. We may

attempt to explain phenomena, but to create for this purpose elastic

ethereal media or substances without direct evidential phenomena in

support is not to advance real knowledge. There are certain properties

peculiar to the luminous as to all other incepting fields, certain

conditions under which each respectively will act, and the true method

of gaining real insight into these agencies is by the study of these

actual properties (or phenomena) and conditions, and not by attempts to

ultimately explain them. It will be evident that in most cases of

natural energy operations there is more than one energy influence in

action. As a rule there are several. In a growing plant, for example, we

have the thermal, luminous, gravitation, and cohesive influences all in

operation at the same time, each performing its peculiar function in

transformation, each contributing its own peculiar energy phenomena to

the whole. This feature adds somewhat to the complexity of natural

operations and to the difficulties in the precise description of the

various phenomena with which they are associated.

20. _Transformations--Upward Movement of a Mass against Gravity_

When the significance of energy inception and the characteristic

properties of the various agencies have been grasped, it becomes much

easier to deal with certain other aspects of energy processes. To

illustrate these aspects it is, therefore, now proposed to discuss a few

simple secondary operations embodied in experimental apparatus. A few

examples of the operations of transformation and transmission of energy

will be considered. The object in view is to show the general nature of

these processes, and more especially the limits imposed upon them by the

various factors or properties of the material machines in which they are

of necessity embodied. The reader is asked to bear in mind also the

observations already made (Sec. 13) with respect to experimental apparatus

generally.

The first operation for discussion is that of the upward movement of a

mass of material against the gravitative attraction of the earth. This

movement involves one of the most simple and at the same time one of the

most important of secondary energy processes. As a concrete

illustration, consider the case of a body projected vertically upwards

with great velocity from the surface of the earth. The phenomena of its

motion will be somewhat as follows:--As the body recedes from the

earth's surface in its upward flight, its velocity suffers a continuous

decrease, and an altitude is finally attained where this velocity

becomes zero. The projectile, at this point, is instantaneously at rest.

Its motion then changes; it commences to fall, and to proceed once more

towards the starting-point with continuously increasing velocity.

Neglecting the effect of the air (Sec. 29) and the rotational movement of

the earth, it may be assumed that the retardation of the projectile in

its upward flight is numerically equal to its acceleration in its

downward flight, and that it finally returns to the starting-point with

velocity numerically equal to the initial velocity of projection. The

process then obviously involves a complete transformation and return of

energy. At the earth's surface, where its flight commences and

terminates, the body is possessed of energy of motion to a very high

degree. At the highest point of flight, this form of energy has entirely

vanished; the body is at rest. Its energy properties are then

represented by its position of displacement from the earth's surface;

its energy of motion in disappearing has assumed this form of energy of

position, energy of separation, or potential energy. The moving body has

thus been the mechanism of an energy transformation. At each stage of

its upward progress, a definite modicum of its original energy of motion

is converted into energy of position. Between the extreme points of its

flight, the energy of the body is compounded of these two forms, one of

which is increasing at the expense of the other. When the summit of

flight is reached the conversion into energy of position is complete. In

the downward motion, the action is completely reversed, and when the

body reaches the starting-point its energy of position has again been

completely transformed into energy of motion. It might be well to draw

attention here to the fact, often overlooked, that this energy of

position gained by the rising mass is, in reality, a form of energy,

separate and distinct, brought into existence by the transformation and

disappearance of the energy of the moving mass. Energy of position is as

truly a form of energy as heat or kinetic energy.

The transformation here depicted is clearly a simple process, yet we

know absolutely nothing of its ultimate nature, of the why or wherefore

of the operation. Our knowledge is confined to the circumstances and

conditions under which it takes place. Let us now, therefore, deal with

these conditions. The transformation is clearly carried out in virtue of

the movement of the body in the lines or field of an incepting

influence. This influence is that of gravitation, which links the body

continually to the earth. Now the function of gravitation in this

process, as in others already described, is that of a completely passive

incepting agent. The active energy which suffers change in the process

is clearly the original work energy (Sec. 31) communicated to the projected

body. The whole process is, in fact, a purely mechanical operation, and

as in the case of other processes involving mechanical energy, it is

limited by the mass value of the moving material. It is clear that the

greater the amount of energy communicated to the projectile at the

starting-point, the greater will be the altitude it will attain in its

flight. The amount of energy, however, which can thus be communicated is

dependent on the maximum force which can be applied to the projectile.

But the maximum force which can be applied to any body depends entirely

on the resistance offered by that body, and in this case the resisting

force is the gravitative attraction of the earth on the projectile,

which attraction is again a direct function of its mass. The greater the

mass, the greater the gravitative force, and the greater the possibility

of transformation. The ultimate limit of the process would be reached if

the projected mass were so great as to equal half the mass of the earth.

In such circumstances, the earth being assumed to be divided into two

equal masses, the maximum limiting value of the gravitative attraction

would clearly be attained. Any increase of the one mass over the other

would again lead, however, to a diminution in the attractive force and a

corresponding decrease in the energy limit for transformation. The

precise manner in which the operations of mechanical energy are limited

by the mass will now be clear. The principle is quite general, and

applicable to all moving bodies. Mass is ever a direct measure of energy

capacity. A graphical method of representing energy transformations of

this kind, by a system of co-ordinates, would enable the reader to

appreciate more fully the quantitative relations of the forms of energy

involved and also their various limits.

21. _The Simple Pendulum_

The remaining operations of transformation for discussion are embodied

in the following simple apparatus. A spherical metallic mass M (Fig. 2)

is supported by a rod P which is rigidly connected to a horizontal

spindle HS as shown.

[Illustration: FIG. 2]

The spindle is supported and free to revolve in the bearings B{1} and

B{2} which form part of the supporting framework V resting on the

ground; the bearing surfaces at B{1} and B{2} are lubricated, and the

mass M is free to perform, in a vertical plane, complete revolutions

about the axis through the centre of the spindle. In carrying out this

motion its path will be circular, as shown at DCFE; the whole

arrangement is merely an adaptation of the simple pendulum. As

constituted, the apparatus may form the seat of certain energy

operations. Some of these will only take place with the application of

energy of motion to the pendulum from an external source, thereby

causing it to vibrate or to rotate: others, again, might be said to be

inherent to the apparatus, since they arise naturally from its

construction and configuration. We shall deal with the latter first.

22. _Statical Energy Conditions_

The pendulum with its spindle has a definite mass value, and, assuming

it to be at rest in the bearings B{1} and B{2}, it is acted upon by

gravitation, or in other words, it is under the influence or within the

field of the gravitative attraction of the earth's mass upon it. The

effect of this field is directly proportional to the mass of the

pendulum and spindle, and to its action is due that bearing pressure

which is transmitted through the lubricant to the bearing surfaces and

thence to the supporting arms N{1} and N{2} of the framework. Bearings

and columns alike are thus subjected to a downward thrust or pressure.

Being of elastic material, they will be more or less distorted. This

distortion will proceed until the downward forces are balanced by the

upward or reactive forces called into play in virtue of the cohesive

properties of the strained material. Corresponding to a slight downward

movement of the pendulum and spindle in thus straining or compressing

them, the supporting columns will be decreased in length. This downward

movement is the external evidence of certain energy operations. In

virtue of their elevation above the earth's surface, the pendulum and

spindle possess, to a certain degree, energy of position, and any free

downward movement would lead to the transformation of this energy into

energy of motion (Sec. 20). But the downward motion of pendulum and spindle

is not free. It is made against the resistance of the material of the

supporting columns, and the energy of position, instead of assuming the

form of energy of motion, is simply worked down or transformed against

the opposing cohesive forces of the supporting materials. This energy,

therefore, now resides in these materials in the form of energy of

strain or distortion. In general nature, this strain energy is akin to

energy of position (Sec. 20). Certain portions of the material of the

columns have been forced into new positions against the internal forces

of cohesion which are ever tending to preserve the original

configuration of the columns. This movement of material in the field of

the cohesive influence involves the transformation of energy (Sec. 4), and

the external evidence of the energy process is simply the strained or

distorted condition of the material. If the latter be released, and

allowed to resume its natural form once more, this stored energy of

strain would be entirely given up. In reality, the material can be said

to play the part of a machine or mechanism for the energy process of

storage and restoration. No energy process, in fact, ever takes place

unless associated with matter in some form. The supporting arms, in this

case, form the material factor or agency in the energy operation. All

such energy machines, also, are limited in the extent of their

operation, by the qualities of the material factors. In this particular

case, the energy compass of the machine is restricted by certain

physical properties of the material, by the maximum value of these

cohesive or elastic forces called into play in distortion. These forces

are themselves the evidence of energy, of that energy by virtue of which

the material possesses and maintains its coherent form. In this case

this energy is also the factor controlling the transformation, and

appears as a separate and distinct incepting agency. If the process is

to be a reversible one, so that the energy originally stored in the

material as strain energy or energy of distortion may be completely

returned, the material must not be stressed beyond a certain point. Only

a limited amount of work can be applied to it, only a limited amount of

energy can be stored in it. Too much energy applied--too great a weight

on the supporting columns--gives rise to permanent distortion or

crushing, and an entirely new order of phenomena. This energy limit for

reversibility is then imposed by the cohesive properties of the material

or by its elastic limits. Up to this point energy stored in the material

may be returned--the process is reversible in nature--but above this

elastic limit any energy applied must operate in an entirely different

manner.

A little consideration will show also, that the state of distortion, or

energy strain, is not confined to the material of the supporting columns

alone. Action and reaction are equal. The same stresses are applied to

the spindle through the medium of bearings and lubricant. In fact, every

material substance of which the pendulum machine is built up is thus,

more or less, strained against internal forces; all possess, more or

less, cohesion or strain energy. It will be evident, also, that this

condition is not peculiar to this or any other form of apparatus. It is

the energy state or condition of every structure, either natural or

artificial, which is built up of ordinary material, and which, on the

earth's surface, is subjected to the influence of the gravitation field.

This cohesion or strain energy is one of the forms in which energy is

most widely distributed throughout material.

In reviewing the statical condition of the above apparatus, the pendulum

itself has been assumed to be hanging vertically at rest under the

influence of gravitation. If energy be now applied to the system from

some external source so that the pendulum is caused to vibrate, or to

rotate about the axis of suspension, a new set of energy processes make

their appearance. The movement of the pendulum mass, in its circular

path around the central axis, is productive of certain energy reactions,

as follows:--

_a._ A transformation of energy of motion into energy of position

and vice versa.

_b._ A frictional transformation at the bearing surfaces.

These processes will each be in continuous operation so long as the

motion of the pendulum is maintained. Their general nature is quite

independent of the extent of that motion, whether it be merely vibratory

through a small arc, or completely rotatory about the central axis. In

the articles which immediately follow, the processes will be treated

separately.

23. _Transformations of the Moving Pendulum--a. Energy of Motion to

Energy of Position and Vice Versa_

In this simple transformation the motion of the pendulum about the axis

of suspension may be either vibratory or circular, according to the

amount of energy externally applied. In each case, every periodic

movement of the apparatus illustrates the whole energy operation. The

general conditions of the process are almost identical with those in the

case of the upward movement of a mass against gravity (Sec. 20).

Gravitation is the incepting energy influence of the operation. If the

pendulum simply vibrates through a small arc, then, at the highest

points of its flight, it is instantaneously at rest. Its energy of

motion is here, therefore, zero; its energy of position is a maximum. At

the lowest point of its flight, the conditions are exactly reversed.

Here its energy of motion is a maximum, while its energy of position

passes through a minimum value. The same general conditions hold when

the pendulum performs complete revolutions about the central axis. If

the energy of motion applied is just sufficient to raise it to the

highest point E (Fig. 2), the mass will there again be instantaneously

at rest with maximum energy of position. As the mass falls downwards in

completing the circular movement, its energy of position once more

assumes the kinetic form, and reaches its maximum value at C (Fig. 2),

the lowest position. The moving pendulum mass, so far as its energy

properties are concerned, behaves in precisely the same manner as a body

vertically projected in the field of the gravitative attraction (Sec. 20).

This simple energy operation of the pendulum is perhaps one of the most

familiar of energy processes. By its means, however, it is possible to

illustrate certain general features of energy reactions of great

importance to the author's scheme.

The energy processes of the pendulum system are carried out through the

medium of the material pendulum machine, and are limited, both in nature

and degree, by the properties of that machine. As the pendulum vibrates,

the transformation of energy of motion to energy of position or vice

versa is an example of a reversible energy operation. The energy active

in this operation continually alternates between two forms of energy:

transformation is continually followed by a corresponding return.

Neglecting in the meantime all frictional and other effects, we will

assume complete reversibility, or that the energy of motion of the

pendulum, after passing completely into the form of energy of position

at the highest point, is again completely returned, in its original

form, in the descent. Now, for any given pendulum, the amount of energy

which can thus operate in the system depends on two factors, namely, the

mass of the pendulum and the vertical height through which it rises in

vibration. If the mass is fixed, then the maximum amount of energy will

be operating in the reversible cycle when the pendulum is performing

complete revolutions round its axis of suspension. The maximum height

through which the pendulum can rise, or the maximum amount of energy of

position which the system can acquire, is thus dependent on the length

of the pendulum arm. These two factors, then, the mass and the length of

the pendulum arm, are simply properties of this pendulum machine,

properties by which its energy compass is restricted. Let us now

examine these limiting factors more minutely.

It is obvious that energy could readily be applied to the pendulum

system in such a degree as to cause it to rotate with considerable

angular velocity about the axis of suspension. Now the motion of the

pendulum mass in the lines of the gravitation field, although productive

of the same transformation process, differs from that of a body moving

vertically upward in that, while the latter has a linear movement, the

former is constrained into a circular path. This restraint is imposed in

virtue of the cohesive properties of the material of the pendulum arm,

and it is the presence of this restraining influence that really

distinguishes the pendulum machine from the machine in which the moving

mass is constrained by gravity alone (Sec. 20). It has been shown that the

energy capacity of a body projected vertically against gravity is

limited by its mass only; the energy capacity of the pendulum machine

may be likewise limited by its mass, but the additional restraining

factor of cohesion also imposes another limit. In the course of

rotation, energy is stored in the material of the pendulum against the

internal forces of cohesion. The action is simply that of what is

usually termed centrifugal force. As the velocity increases, the

pendulum arm lengthens correspondingly until the elastic limit of the

material in tension is reached. At this point, the pendulum may be said

to have reached the maximum length at which it can operate in that

reversible process of transformation in which energy of motion is

converted into energy of position. The amount of energy which would now

be working in that process may be termed the limiting energy for

reversibility. This limiting energy is the absolute maximum amount of

energy which can operate in the reversible cycle. It is coincident with

the maximum length of the pendulum arm in distortion. When the stress in

the material of that arm reaches the elastic limit, it is clear that the

transformation against cohesion will also have attained its limiting

value for reversibility. This transformation, if the velocity of the

pendulum is constant, is of the nature of a storage of energy. So long

as the velocity is constant the energy stored is constant. If the

elastic limiting stress of the material has not been exceeded, this

energy--neglecting certain minor processes (Secs. 15, 29)--will be returned

in its original form as the velocity decreases. If, however, the

material be stressed beyond its elastic powers, the excess energy

applied will simply lead to permanent distortion or disruption of the

pendulum arm, and to a complete breakdown and change in the character of

the machine and the associated energy processes (Sec. 5). The physical

properties of the material thus limit the energy capacity of the

machine. This limiting feature, as already indicated, is not peculiar

to the pendulum machine alone. Every energy process embodied in a

material machine is limited in a similar fashion by the peculiar

properties of the acting materials. Every reversible process is carried

out within limits thus clearly defined. Nature presents no exception to

this rule, no example of a reversible energy system on which energy may

be impressed in unlimited amount. On the contrary, all the evidence

points to limitation of the strictest order in such processes.

24. _Transformations of the Moving Pendulum--b. Frictional

Transformation at the Bearing Surfaces_

The motion of the pendulum, whether it be completely rotatory or merely

vibratory in nature, invariably gives rise to heating at the bearings or

supporting points. Since the heating effect is only evident when motion

is taking place, and since the heat can only make its appearance as the

result of some energy process, it would appear that this persistent heat

phenomenon is the result of a transformation of the original energy of

motion of the pendulum.

The general energy conditions of the apparatus already adverted to (Sec.

21) still hold, and the lubricating oil employed in the apparatus being

assumed to have sufficient capillarity or adhesive power to separate

the metallic surfaces of bearings and journals at all velocities, then

every action of the spindle on the bearings must be transmitted through

the lubricant. The latter is, therefore, strained or distorted against

the internal cohesive or viscous forces of its material. The general

effect of the rotatory motion of the spindle will be to produce a motion

of the material of the lubricant in the field of these incepting forces.

To this motion the heat transformation is primarily due. Other

conditions being the same, the extent of the transformation taking

place, in any given case, is dependent on the physical properties of the

lubricant, such as its viscosity, its cohesive or capillary power,

always provided that the metallic surfaces are separated, so that the

action is really carried out in the lines or field of the internal

cohesive forces of the lubricant. In itself, this transformation is not

a reversible process; no mechanism appears by which this heat energy

evolved at the bearing surfaces could be returned once more to its

original form of energy of motion. It may be, in fact, communicated by

conduction to the metallic masses of the bearings, and thence, by

conduction and radiation, to the air masses surrounding the apparatus.

Its action in these masses is dealt with below (Sec. 29). The operation of

bearing friction, though in itself not a reversible process, really

forms one link of a complete chain (Sec. 9) of secondary operations

(transmissions and transformations) which together form a comprehensive

and complete cyclical energy process (Sec. 32).

When no lubricant is used in the apparatus, so that the metallic

surfaces of bearings and journals are in contact, the heat process is of

a precisely similar nature to that described above (see also Sec. 16).

Distortion of the metals in contact takes place in the surface regions,

so that the material is strained against its internal cohesive forces.

The transformation will thus depend on the physical properties of these

metals, and will be limited by these properties. Different metallic or

other combinations will consequently give rise to quite different

results with respect to the amounts of heat energy evolved.

25. _Stability of Energy Systems_

The ratio of the maximum or limiting energy for reversibility to the

total energy of the system may vary in value. If the pendulum vibrates

only through a very small arc, then, neglecting the minor processes (Secs.

24, 29), practically the whole energy of the system operates in the

reversible transformation. This condition is maintained as the length of

the arc of vibration increases, until the pendulum is just performing

complete revolutions about the central axis. After this, the ratio will

alter in value, because the greater part of any further increment of

energy does not enter into the reversible cyclical process, but merely

goes to increase the velocity of rotation and the total energy of the

system. The small amount of energy which thus enters the reversible

cycle as the velocity increases, does so in virtue of the increasing

length of the pendulum arm in distortion. To produce even a slight

distortion of the arm, a large amount of energy will require to be

applied to and stored in the system, and thus, at high velocities of

rotation, the energy which operates in the reversible cycle, even at its

limiting value, may form only a very small proportion of the total

energy of the system. At low velocities or low values of the total

energy, say when the pendulum is not performing complete rotations,

practically the whole energy of the system is working in the reversible

cycle; but, in these circumstances, it is clear that the total energy of

the system, which, in this case, is all working in the reversible

process, is much less than the maximum or limiting amount of energy

which might so work in that process. Under these conditions, when the

total energy of the system is less than the limiting value for

reversibility, so that this total energy in its entirety is free to take

part in the reversible process, then the energy system may be termed

stable with respect to that process. Stability, in an energy system,

thus implies that the operation considered is not being, as it were,

carried out at full energy capacity, but within certain reversible

energy limits.

We have emphasised this point in order to draw attention to the fact

that the great reversible processes which are presented to our notice in

natural phenomena are all eminently stable in character. Perhaps the

most striking example of a natural reversible process is found in the

working of the terrestrial atmospheric machine (Secs. 10, 38). The energy

in this case is limited by the mass, but in actual operation its amount

is well within the maximum limiting value. The machine, in fact, is

stable in nature. Other natural operations, such as the orbital

movements of planetary masses, (Sec. 8) illustrate the same conditions.

Nature, although apparently prodigal of energy in its totality, yet

rigidly defines the bounding limits of her active operations.

26. _The Pendulum as a Conservative System_

Under certain conditions the reversible energy cycle produces an

important effect on the rotatory motion of the pendulum. For the purpose

of illustration, let it be assumed that the pendulum is an isolated and

conservative system endowed with a definite amount of rotatory energy.

In its circular movement, the upward motion of the pendulum mass is

accompanied by a gain in its energy of position. This gain is, in the

given circumstances, obtained solely at the expense of its inherent

rotatory energy, which, accordingly, suffers a corresponding decrease.

The manifestation of this decrease will be simply a retardation of the

pendulum's rotatory motion. Its angular velocity will, therefore,

decrease until the highest altitude E (Fig. 2) is attained. After this,

on the downward path, the process will be reversed. Acceleration will

take place from the highest to the lowest point of flight, and the

energy stored as energy of position will be completely returned in its

original form of energy of motion. The effect of the working of the

reversible cycle, then, on the rotatory system, under the given

conditions, is simply to produce alternately a retardation and a

corresponding acceleration. Now, it is to be particularly noted that

these changes in the velocity of the system are produced, not by any

abstraction from or return of energy to the system, which is itself

conservative, but simply in consequence of the transformation and

re-transformation of a certain portion of its inherent rotatory energy

in the working of a reversible process embodied in the system. The same

features may be observed in other systems where the conditions are

somewhat similar.

In the natural world, we find processes of the same general nature in

constant operation. When any mass of material is elevated from the

surface of a rotating planetary body against the gravitative attraction,

it thereby gains energy of position (Sec. 20). This energy, on the body's

return to the surface in the course of its cycle, reappears in the form

of energy of motion. Now the material mass, in rising from the planetary

surface, is not, in reality, separated from the planet. The atmosphere

of the planet forms an integral portion of its material, partakes of its

rotatory motion, and is bound to the solid core by the mutual

gravitative forces. Any mass, then, on the solid surface of a planet is,

in reality, in the planetary interior, and the rising of such a mass

from that surface does not imply any actual separative process, but

simply the radial movement, or displacement of a portion of the

planetary material from the central axis. If the energy expended in the

upraisal of the mass is derived at the expense of the inherent rotatory

energy of the planet, as it would be if the latter were a strictly

conservative energy system, then the raising of this portion of

planetary material from the surface would have a retarding effect on the

planetary motion of rotation. But if, on the other hand, the energy of

such a mass as it fell towards the planetary surface were converted once

more into its original form of energy of axial motion, exactly

equivalent in amount to its energy of position, it is evident that the

process would be productive of an accelerating effect on the planetary

motion of rotation, which would in magnitude exactly balance the

previous retardation. In such a process it is evident that energy

neither enters nor leaves the planet. It simply works in an energy

machine embodied in planetary material. This point will be more fully

illustrated later. The reader will readily see the resemblance of a

system of this nature to that which has already been illustrated by the

rotating pendulum.

In the meantime, it may be pointed out that matter displaced from the

planetary surface need not necessarily be matter in the solid form. All

the operations mentioned above could be quite readily--in fact, more

readily--carried out by the movements of gaseous material, which is

admirably adapted for every kind of rising, falling, or flowing motion

relative to the planetary surface (Sec. 13).

27. _Some Phenomena of Transmission Processes--Transmission of Heat

Energy by Solid Material_

The pendulum machine described above furnishes certain outstanding

examples of the operation of energy transformation. It will be noted,

however, that it also portrays certain processes of energy transmission.

In this respect it is not peculiar. Most of the material machines in

which energy operates will furnish examples of both energy transmissions

and energy transformations. In some instances, the predominant operation

seems to be transformation, in others, transmission; and the machines

may be classified accordingly. It is, however, largely a matter of

terminology, since both operations are usually found closely associated

in one and the same machine. The apparatus now to be considered is

designed primarily to illustrate the operative features of certain

energy transmissions, but the description of the machines with their

allied phenomena will show that energy transformations also play a very

important part in their constitution and working.

A cylindrical metallic bar about twelve inches long, say, and one inch

in diameter, is placed with its ends immersed in water in two separate

vessels, A and B, somewhat as shown.

[Illustration: FIG. 3]

By the application of heat energy, the temperature of the water in the

vessel A is raised to a point say 100 deg. F. above that of B, and steadily

maintained at that point. It is assumed that B is also kept at the

constant lower temperature. In these circumstances, a transmission of

heat energy takes place from A to B through the metallic bar. When the

steady temperature condition is reached, the transmission will be

continuous and uniform; the rate at which it is carried out will be

determined by the length of the bar, by the material of which it is

composed, and by the temperature difference maintained between its

ends. Now what has really happened is that by a combination of

phenomena the bar has been converted into a machine for the transmission

of heat energy. A full description of these phenomena is, in reality,

the description of this machine, and vice versa. Let us, therefore, now

try to outline some of these phenomena.

The first feature of note is the gradient of temperature which exists

between the ends of the bar. Further research is necessary regarding the

real nature of this gradient--it appears to differ greatly in different

materials--but the existence of such a gradient is one of the main

features of the energy machine, one of the essential conditions of the

transmission process.

Another feature is that of the expansive motion of the bar itself. The

expansion of the bar due to the heating varies in value along its

length, from a maximum at the hot end to a minimum at the cool end. The

expansion, also, is the evidence of a transformation of energy. The bar

has been constrained into its new form against the action of the

internal molecular or cohesive forces of its material (Sec. 16). The energy

employed and transformed in producing the expansion is a part of the

original heat energy applied to the bar, and before any transmission of

this heat energy takes place between its extreme ends, a definite

modicum of the applied energy has to be completely transformed for the

sole purpose of producing this distortive movement or expansion against

cohesion. This preliminary straining of the bar is, in fact, a part of

the process of building up or constituting the energy transmission

machine, and must be completely carried out before any transmission can

take place. It is clear, then, that concurrent with the gradient of

temperature, there also exists, along the bar, what might be termed a

gradient of energy stored against cohesion, and that both are

characteristic and essential features of this particular energy machine.

A point of some importance to note is the permanency of these features.

Once the machine has been constituted with a constant temperature

difference, the transmission of energy will take place continuously and

at a uniform rate. But no further transformation against cohesion takes

place; no further expenditure of energy against the internal forces of

the material is necessary. Neglecting certain losses due to possible

external conditions, the whole energy applied to the machine at the one

end is transmitted in its entirety to the other, without influencing in

any way either the temperature or the energy gradient.

Such is the general constitution of this machine for energy

transmission. Its material foundation is, indeed, the metallic bar, but

the temperature and energy gradients may be termed the true determining

factors of its operation. As already indicated, the magnitude of the

transformation is dependent on the temperature difference between the

ends of the bar. But this applies only within certain limits. With

respect to the cool end, the temperature may be as low as we please--so

far as we know, the limit is absolute zero of temperature; but with the

hot end, the case is entirely different, because here the limit is very

strictly imposed by the melting-point of the material of the bar. When

this melting temperature is attained, the melting of the bar indicates,

simply, that the heat energy stored or transformed against the cohesive

forces of the material has reached its limiting value; change of state

of the material is taking place, and the machine is thereby being

destroyed.

It is evident, then, that the energy which is actually being transmitted

has itself no effect whatever in restricting the action or scope of the

transmission machine. It is, in reality, the residual energy stored

against the cohesive forces which imposes the limits on the working. It

is the maximum energy which can be transformed in the field of the

cohesive forces of the material which determines the power of that

material as a transmitting agent. This maximum will, of course, be

different for different materials according to their physical

constitution. It is attained in this machine in each case when melting

of the bar takes place.

28. _Some Phenomena of Transmission Processes--Transmission by Flexible

Band or Cord_

This method is often adopted when energy of motion, or mechanical

energy, is required to be transmitted from one point to another. For

illustration, consider the case of two parallel spindles or shafts, A

and B (Fig. 4), each having a pulley securely keyed upon it. Spindle A

is connected to a source of of mechanical energy, and it is desired to

transmit this energy across the intervening space to spindle B.

[Illustration: FIG. 4]

This, of course, might be accomplished in various ways, but one of the

most simple, and, at the same time, one of the most efficient, is the

direct drive by means of a flexible band or cord. The band is placed

tightly round, and adheres closely to both pulleys; the coefficient of

friction between band and pulleys may, in the first instance, be assumed

to be sufficiently great to prevent slipping of the band up to the

highest stress which it is capable of sustaining in normal working.

Connected in this fashion, the spindles will rotate in unison, and

mechanical energy, if applied at A, may be directly transmitted to B.

The material operator in the transmission is the connecting flexible

band, and associated with this material are certain energy processes

which are also essential features of the energy machine. When

transmission of energy is taking place, a definite tension or stress

exists in the connecting band, and neglecting certain inevitable losses

due to bearing friction (Sec. 24) and windage (Sec. 29), practically the whole

of the mechanical or work energy communicated to the one spindle is

transmitted to the other. Now the true method of studying this or any

energy process is simply to describe the constitution and principal

features of the machine by which it is carried out. These are found in

the phenomena of transmission. One of the most important is the peculiar

state of strain or tension existing in the connecting band. This, as

already indicated, is an absolutely essential condition of the whole

operation. No transmission is possible without some stress or pull in

the band. This pull is exerted against the cohesive forces of the

material of the band, so that before transmission takes place it is

distorted and a definite amount of the originally applied work energy is

expended in straining it against these forces. This energy is

accordingly stored in the form of strain energy or energy of separation

(Sec. 22), and, if the velocity is uniform, the magnitude of the

transmission is proportional to this pull in the band, or to the

quantity of energy thus stored against the internal forces of its

material. But, in every case, a limit to this amount of energy is

clearly imposed by the strength of the band. The latter must not be

strained beyond its limiting elastic stress. So long as energy is being

transmitted, a certain transformation and return of energy of strain or

separation is taking place in virtue of the differing values of the

tensions in the two sides of the band; and if the latter were stressed

beyond the elastic limit, permanent distortion or disruption of the

material would take place. Under such conditions, the reversible energy

process, involving storage and restoration of strain energy as the band

passes round the pulleys, would be impossible, and the energy

transmission machine would be completely disorganised. The magnitude of

the energy operation is thus limited by the physical properties of the

connecting band.

Another important feature of this energy transmission machine is the

velocity, or rather the kinetic energy, of the band. The magnitude of

the transmission process is directly proportional to this velocity, and

is, therefore, also a function of the kinetic energy. At any given rate

of transmission, this kinetic energy, like the energy stored against the

cohesive influence, will be constant in amount, and like that energy

also, will have been obtained at the expense of the originally applied

energy. This kinetic energy is an important feature in the constitution

of the transmission machine. As in the case of the strain energy, its

maximum value is strictly limited, and thus imposes a limit on the

general operation of the machine. For, at very high velocities, owing to

the action of centrifugal force, it is not possible to keep the band in

close contact with the surface of the pulleys. When the speed rises

above a certain limit, although the energy actually being transmitted

may not have attained the maximum value possible at lower speeds with

greater tension in the band, the latter will, in virtue of the strain

imposed by centrifugal action, be forced radially outwards from the

pulley. The coefficient of friction will be thereby reduced; slipping

will ensue, and the transmission may cease either in whole or in part.

In this way the velocity or kinetic energy limit is imposed. The machine

for energy transmission may thus be limited in its operation by two

different factors. The precise way in which the limit will be applied in

any given case will, of course, depend on the circumstances of working.

29. _Some Phenomena of Transmission Processes--Transmission of Energy to

Air Masses_

The movement of the pendulum (Sec. 23) is accompanied by a certain

transmission of energy to the surrounding medium. When this medium is a

gaseous one such as air, the amount of energy thus transmitted is

relatively small. The process, however, has a real existence. To

illustrate its general nature, let it be assumed that the motion of the

pendulum is carried out, not in air, but in a highly viscous fluid, say

a heavy oil. Obviously, a pendulum falling from its highest position to

its lowest, in such a medium would transmit its energy almost in its

entirety to the medium, and would reach its lowest position almost

devoid of energy of motion. The energy of position with which it was

originally endowed would thus be transformed and transmitted to the

surrounding medium. The agent by which the transmission is carried out

is the moving material of the pendulum, which, as it passes through the

fluid, distorts that fluid in the lines or field of its internal

cohesive or viscous forces which offer a continuous resistance to the

motion. As the pendulum passes down through the liquid, the succeeding

layers of the latter are thus alternately distorted and released. The

distortive movement takes place in virtue of the communication of energy

from the moving pendulum to the liquid, and during the movement energy

is stored in the fluid as energy of strain and as kinetic energy. At the

same time, a transformation of the applied energy into heat takes place

in the distorted material. The release of this material from strain, and

its movement back towards its original state, is also accompanied by a

similar transformation, in which the stored strain energy is, in turn,

converted into the heat form. The whole operation is similar in nature

to that frictional process already described (Sec. 16) in the case of a

body moving on a rough horizontal table. The final action of the heat

energy thus communicated to the fluid is to expand the latter against

the internal cohesive or viscous forces of its material, and also

against the gravitative attraction of the earth.

Now when the pendulum moves in air, the action taking place is of the

same nature, and the final result is the same as in oil. It differs

merely in degree. Compared with the oil, the air masses offer only a

slight resistance to the motion, and thus only an exceedingly small part

of the pendulum's energy is transmitted to them. The pendulum, however,

does set the surrounding air masses in motion, and by a process similar

in nature to that in the oil, a modicum of the energy of the falling

pendulum is converted into heat, and thence by the expansion of the air

into energy of position. In the downward motion from rest, the first

stage of the process is a transformation peculiar to the pendulum

itself, namely, energy of position into energy of motion. The

transmission to the fluid is a necessary secondary result. It is

important to note that this transmission is carried out in virtue of the

actual movement of the material of the pendulum, and that the energy

transmitted is in reality mechanical or work energy (Sec. 31). This

mechanical or work energy, then actually leaves or is transmitted from

the pendulum system, and is finally absorbed by the surrounding air

masses in the form of energy of position.

Considered as a whole, there is evidently no aspect of reversibility

about the operation, but it will be shown later (Sec. 32) that with the

introduction of other factors, it really forms part of a comprehensive

cyclical process. It is itself a process of direct transmission. It is

carried out by means of a definite material machine which embodies

certain energy transformations, and which is strictly limited in the

extent of its operations by certain physical factors. These factors are

the cohesive properties of the moving pendulum mass and the fluid with

which it is in contact (Sec. 16). It is clear, also, that in an apparatus

in which the motion is carried out in oil, any heat energy communicated

to the oil would inevitably find its way to the surrounding air masses

by conduction and radiation. The final result of the pendulum's motion

would therefore be the same in this case as in air; the heat energy

would, when communicated to the surrounding air masses, cause an

expansive movement against gravity.

30. _Energy Machines and Energy Transmission_

[Illustration: FIG. 5]

The various examples of energy transformation and transmission which

have been discussed above (Secs. 13-27) will suffice to show the essential

differences which exist in the general nature of these operations. But

they will also serve another purpose in portraying one striking and

important aspect in which these processes are alike. From the

descriptions given above, it will be amply evident that each of these

processes, whether transformation or transmission, requires as an

essential condition of its existence, the presence of a certain

arrangement of matter; each process is of necessity associated with and

embodied in a definite physical and material machine. This material

machine is simply the contrivance provided by Nature to carry out the

energy operation. It differs in construction and in character for

different processes, but in every case there must be in its constitution

some material substance, perceptible to the senses, with which the

acting energy is intimately associated. This fact is but another aspect

of the principle that energy is never found dissociated from matter (Sec.

11). In every energy machine, the material substance or operator forms

the real foundation or basis of the energy operation, but besides this

there are also always other phenomena of a secondary nature, totally

different, it may be, from the main energy operation, which combine with

that operation to constitute the whole. These subsidiary energy

phenomena are the incepting factors, and are most important

characteristics. Their presence is just as essential in energy

transmission as it is in energy transformation. As demonstrated above,

they are usually associated with the physical peculiarities of the basis

or acting material of the energy machine, and their peculiar function is

to conserve or limit the extent of its action. A complete description of

these phenomena, in any given case, would not only be equivalent to a

complete description of the machine, but would also serve as a complete

description of the main energy operation embodied in that machine.

Sometimes, however, the description of the machine is a matter of

extreme difficulty, and may be, in fact, impossible owing to the lack of

a full knowledge of the intimate phenomena concerned. An illustrative

example of this is provided by the familiar phenomenon of heat

radiation. Take the case of two isolated solid bodies A and B (Fig. 5)

in close proximity on the earth's surface. If the body A at a high

temperature be sufficiently near to B at a lower temperature, a

transmission of energy takes place from A to B. This transmission is

usually attributed to "radiation," but, after all, the use of the term

"radiation" is merely a descriptive device which hides our ignorance of

the operation. It is known that a transmission takes place, but the

intimate phenomena are not known, and, accordingly, it is impossible to

describe the machine or mechanism by which it is carried out. From

general considerations, however, it appears that the material basis of

this machine is to be found in the air medium which surrounds the two

bodies. Experiment shows, indeed, that if this intervening material

medium of air be even partially withdrawn or removed, the transmission

is immensely reduced in amount. In fact, this latter phenomenon is

largely taken advantage of in the so-called vacuum flasks or other

devices to maintain bodies at a temperature either above or below that

of the external surrounding bodies. The device adopted is, simply, as

far as practicable to withdraw all material connection between the body

which it is desired to isolate thermally and its surroundings. But it is

clearly impossible to isolate completely any terrestrial body in this

way. There must be some material connection remaining. As already

pointed out (Sec. 5), we have no experimental experience of really separate

bodies or of an absolute vacuum. It is to be noted that any vacuous

space which we can experimentally arrange does not even approximately

reproduce the conditions of true separation prevailing in interplanetary

space. Any arrangement of separate bodies which might thus be contrived

is necessarily entirely surrounded or enclosed by terrestrial material

which, in virtue of its stressed condition, constitutes an energy

machine of the same nature as those already described (Sec. 21). Even

although the air could be absolutely exhausted from a vessel, it is

still quite impossible to enclose any body permanently within that

vessel without some material connection between the body and the

enclosing walls. If for example, as shown in Fig. 6, CC represents a

spherical vessel, completely exhausted, and having two bodies, A and B

at different temperatures, in its interior, it is obvious that if these

bodies are to maintain continuously their relative positions of

separation, each must be united by some material connection to the

containing vessel. But when such a connection is made, say as shown at D

and E (Fig. 7), it is clear that A and B are no longer separate bodies

in the fullest sense of the word, but are now in direct communication

with one another through the supports at D and E and the enclosing sides

of the vessel CC. The practicable conditions are thus far from those of

separate bodies in a complete vacuum. It would seem, indeed, to be

beyond human experimental contrivance to reproduce such conditions in

their entirety. So far as these conditions can be achieved, however,

and judging solely by the experimental results already attained with

respect to the effect of exhaustion on radiation, it may be quite justly

averred that, if the conditions portrayed in Fig. 6 could be realised,

no transmission of energy would take place between two bodies, such as A

and B, completely isolated from one another in a vacuous space. It

appears, in fact, to be a quite reasonable and logical deduction from

the experimental evidence that the energy operation of transmission of

heat from one body to another by radiation is dependent on the existence

between these bodies of a real and material substance which forms in

some way (at present unknown) the transmitting medium or machine. The

difficulty which arises in the description of this machine is due, as

already explained above, simply to lack of knowledge of the intimate

phenomena of its working. Many other energy processes will, no doubt,

occur to the reader in which the same difficulty presents itself, due to

the same cause.

[Illustration: FIG. 6]

In dealing with terrestrial operations generally, and particularly when

transmission processes are under consideration, it is important to

recognise clearly the precise nature of these operations and the

peculiar conditions under which they work. It must ever be borne in mind

that the terrestrial atmosphere is a real and material portion of the

earth's mass, extending from the surface for a limited distance into

space (Sec. 34), and whatever its condition of gaseous tenuity, completely

occupying that space in the manner peculiar to a gaseous substance. When

the whole mass of the planet, including the atmosphere, is taken into

consideration, it is readily seen that all energy operations embodied in

or associated with material on what is usually termed the surface of the

earth take place at the bottom of this atmospheric ocean, or, in

reality, in the interior of the earth. The operations themselves are the

manifestations of purely terrestrial energy, which, by its working in

various devices or arrangements of material is being transformed and

transmitted from one form of matter to another. As will be fully

demonstrated later (Part III.), the nature of the terrestrial energy

system makes it impossible for this energy ever to escape beyond the

confines of the planetary atmospheric envelope. These are briefly the

general conditions under which the study of terrestrial or secondary

energy operations is of necessity conducted, and it is specially

important to notice these conditions when it is sought to apply the

results of experimental work to the discussion of celestial phenomena.

It must ever be borne in mind that even the direct observation of the

latter must always be carried out through the encircling planetary

atmospheric material.

[Illustration: FIG. 7]

In this portion of the work it is proposed to investigate in the light

of known phenomena the possibility of energy transmission between

separate masses. As explained above, the term separate is here meant to

convey the idea of perfect isolation, and the only masses in Nature

which truly satisfy this condition are the celestial and planetary

bodies, separated as they are from one another by interplanetary space

and in virtue of their energised condition (Sec. 5). Since this state of

separation cannot be experimentally realised under terrestrial

conditions, it is obvious, therefore, that no purely terrestrial energy

process can be advanced either as direct verification or direct disproof

of a transmission of energy between such truly separate masses as the

celestial bodies. But as we are unable to experiment directly on these

bodies themselves or across interplanetary space, we are forced of

necessity to rely, for experimental facts and conclusions, on the

terrestrial energy phenomena to which access is possible. As already

indicated in the General Statement (Sec. 11), the same energy is bestowed

on all parts of the cosmical system, and by the close observation of the

phenomena of its action in familiar operations the truest guidance may

be obtained as to its general nature and working. In such

investigations, however, only the actual phenomena of the operation are

of scientific or informative value. There is no gain to real knowledge

in assuming, say in the examination of the phenomena of magnetic

attraction between two bodies, that the one is urged towards the other

by stresses in an intervening ethereal medium, when absolutely no

phenomenal evidence of the existence of such a medium is available. It

may be urged that the conception of an ethereal medium is adapted to the

explanation of phenomena, and appears in many instances to fulfil this

function. But as already pointed out (see Introduction), it is

absolutely impossible to explain phenomena. So-called explanations must

ever resolve themselves simply into revelations of further phenomena.

While the value of true working hypotheses cannot be denied, it is

surely evident that such hypotheses, unless they embody and are under

the limitation of controlling facts, are not only useless, but, from the

misleading ideas they are apt to convey, may even be dangerous factors

in the search for truth. Now, if all speculative ideas or hypotheses are

banished from the mind, and reliance is placed solely on the evidential

phenomena of Nature, the study of terrestrial energy operations leads

inevitably to certain conclusions on the question of energy

transmission. In the first place, it must lead to the denial of what has

been virtually the great primary assumption of modern science, namely,

that a mass of material at a high temperature isolated in interplanetary

space would radiate heat in all directions through that space. Such a

conception is unsupported by our experimental or real knowledge of

radiation. The fact that heat radiation takes place from a hot to a cold

body in whatever direction the latter is placed relatively to the

former, does not justify the assumption that such radiation takes place

in all directions in the absence of a cold body. And since there is

absolutely no manifestation of any real material medium occupying

interplanetary space, no sign of the material agency or machine which

the results of direct experiment have led us to conclude is a necessity

for the transmission process of heat radiation, the whole conception

must be regarded as at least doubtful. Even with our limited knowledge

of radiation, the doctrine of heat radiation through space stands

controverted by ordinary experimental experience. With this doctrine

must fall also the allied conception of the transmission of heat energy

by radiation from the sun to the earth. It is to be noted, however, that

only the actual transmission of heat energy from the sun to the earth is

inadmissible; the _heating effect_ of the sun on the earth, which leads

to the manifestation of terrestrial energy in the heat form, is a

continuous operation readily explained in the light of the general

principle of energy transformation already enunciated (Sec. 4). With

respect to other possible processes of energy transmission between the

sun and the earth or across interplanetary space, the same general

methods of experimental investigation must be adopted. The transmission

of energy under terrestrial conditions is carried out in many different

forms and by the working of a large variety of machines. In every case,

no matter in what form the energy is transmitted, that energy must be

associated with a definite arrangement of terrestrial material

constituting the transmission machine. Each energy process of

transmission has its own peculiar conditions of operation which must be

completely satisfied. By the study of these conditions and the allied

phenomena it is possible to gain a real knowledge of the precise

circumstances in which the process can be carried out. Now let us apply

the knowledge of transmission processes thus gained to the general

celestial case, to the question of energy transmission between truly

separate bodies, and particularly to the case of the sun and the earth.

Do we find in this case any evidence of the presence of a machine for

energy transmission? It is impossible, within the limits of this work,

to deal with all the forms in which energy may be transmitted, but let

the reader review any instance of the transmission of energy under

terrestrial conditions, or any energy-transmission machine with which he

is familiar, noting particularly the essential phenomena and material

arrangements, and let him ask himself if there is any evidence of the

existence of a machine of this kind in operation between the sun and

the earth or across interplanetary space. We venture to assert that the

answer must be in the negative. The real knowledge of terrestrial

processes of energy transmission at command, on which all our deductions

must be based, does not warrant in the slightest degree the assumption

of transmission between the sun and the earth. The most plausible of

such assumptions is undoubtedly that which attributes transmission to

heat radiation, but this has already been shown to be at variance with

well-known facts. The question of light transmission will offer no

difficulty if it be borne in mind that light is not in itself a form of

energy, but merely a manifestation of energy as an incepting influence,

which like other incepting influences of a similar nature, can readily

operate across either vacuous or interplanetary space (Sec. 19).

On these general considerations, deduced from the observation of

terrestrial phenomena, allied with the conception of energy machines and

separate masses in space, the author bases one aspect of the denial of

energy transmission between celestial masses. The doctrine of

transmission cannot be sustained in the face of legitimate scientific

deduction from natural phenomena. In the later parts of this work, and

from a more positive point of view, the denial is completely justified.

31. _Identification of Forms of Energy_

Before leaving the question of energy transmission, there are still one

or two interesting features to be considered. Although energy, as

already pointed out, is ever found associated with matter, this

association does not, in itself, always furnish phenomena sufficient to

distinguish the precise phase in which the energy may be manifested.

Some means must, as a rule, be adopted to isolate and identify the

various forms.

Now one of the most interesting and important features of the process of

energy transmission is that it usually provides the direct means for the

identification of the acting energy. Energy, as it were, in movement, in

the process of transmission, is capable of being detected in its

different phases and recognised in each. The phenomena of transmission

usually serve, either directly or indirectly, to portray the precise

nature of the energy taking part in the operation. One of the most

direct instances of this is provided by the transmission of heat energy.

For illustrative purposes, let it be assumed that a body A, possessed of

heat energy to an exceedingly high degree, is isolated within a

spherical glass vessel CC, somewhat as already shown (Fig. 6). If it be

assumed that the space within CC is a perfect vacuum, and that no

material connection exists between the walls of the vessel and the body

A, the latter is completely isolated, and no means whatever are

available for the detection of its heat qualities (Sec. 30). It may seem

that, if the temperature of the body A were sufficiently high, its

energy state might be detected, and in a manner estimated, by its effect

on the eye or by its luminous properties, but we take this opportunity

of pointing out that luminosity is not invariably associated with high

temperature. On the contrary, many bodies are found in Nature, both

animate and inanimate, which are luminous and affect the eye at

comparatively low temperatures. How then is the energy condition of the

body to be definitely ascertained? The only means whereby it is possible

to identify the energy of the body is by transmitting a portion of that

energy to some other body and observing the resultant phenomena.

Suppose, then, another body, such as B (Fig. 6), at a lower temperature

than A, is brought into contact with A, so that a transmission of heat

energy ensues between the two. The phenomena which would result in such

circumstances will be exactly as already described in the case of the

transmission of energy through a solid (Sec. 27). Amongst other

manifestations it would be noticeable that the material of B was

expanded against its inherent cohesive forces. Now if, instead of a

spherical body such as B, a mercurial thermometer were utilised, the

phenomena would be of precisely the same nature. A definite portion of

the heat energy would be transmitted to the thermometer, and would

produce expansion of the contained fluid. By the amount of this

expansion it becomes possible to estimate the energy condition and

properties of the body A, relative to its surroundings or to certain

generally accepted standard conditions. Thermometric measurement is, in

fact, merely the employment of a process of energy transmission for the

purpose of identifying and estimating the heat-energy properties of

material substances.

In everyday life, rough ideas of heat energy are constantly being

obtained by the aid of the senses. This method is, however, only another

aspect of transmission, for it will be clear that the sensations of heat

and cold are, in themselves, but the evidence of the transformation of

heat energy to or from the body.

The process of energy transmission by a flexible band or cord (Sec. 28)

also provides evidence leading to the identification of the peculiar

form of energy which is being transmitted. At first sight, it would

appear as if this energy were simply energy of motion or kinetic energy.

A little reflection, however, on the general conditions of the process

must dispel this idea, for it is clear that the precise nature of the

energy transmitted has no real connection with the kinetic properties of

the system. The latter, truly, influence the rate of transmission and

impose certain limits, but evidently, if the pull in the band increases

without any increase in its velocity, the actual amount of energy

transmitted by the system would increase without altering in any respect

the kinetic properties. It becomes necessary, then, to distinguish

clearly the energy inherent to, or as it were, latent in the system,

from the energy actually transmitted by the system, to recognise the

difference between the energy transmitted by moving material and the

energy of that material. In this special instance, to identify the form

of energy transmitted it must of necessity be associated with the

peculiar phenomena of transmission. Now the energy is evidently

transmitted by the movement of the connecting belt or band. Before any

transmission can take place, however, a certain amount of energy must be

stored in the moving system, partly as cohesion or strain energy and

partly as energy of motion or kinetic energy. It is this preliminary

storage of energy which, in reality, constitutes the transmission

machine, and for a given rate of transmission, the energy thus stored

will be constant in value. It is obtained at the expense of the applied

energy, and, neglecting certain minor processes, will be returned (or

transmitted) in its entirety when the moving system once more comes to

rest. This stored energy, in fact, works in a reversible process. But

when the transmission machine is once constituted, the energy

transmitted is then that energy which is being continually applied at

the spindle A (Fig. 4) and as continually withdrawn at the spindle B. It

must be emphasised that the energy thus transmitted is absolutely

different from the kinetic or other energy associated with the moving

material of the system. It is the function of this energised material of

the band to transmit the energy from A to B, but this is the only

relationship which the transmitted energy bears to the material. The

energy thus transmitted by the moving material we term mechanical or

work energy. We may thus define mechanical or work energy as "_that form

of energy transmitted by matter in motion_."

The idea of work is usually associated with that of a force acting

through a certain distance. The form of energy referred to above as work

energy is, in the same way, always associated with the idea of a thrust

or of a pressure of some kind acting on moving material. Work energy

thus bears two aspects, which really correspond to the familiar product

of pressure and volume. Both aspects are manifested in transmission.

Since work energy is invariably transmitted by matter in motion, every

machine for its transmission must possess energy of motion as one of its

essential features. As shown above (see also Sec. 28), this energy of

motion is really obtained at the expense of the originally applied work

energy, and as it remains unaltered in value during the progress of a

uniform transmission, it may be regarded as simply transformed work

energy, stored or latent in the system, which will be returned in its

entirety and in its original form at the termination of the operation.

The energy stored against cohesion or other forces may be regarded in

the same way. It is really the manifestation of the pressure or thrust

aspect of the work energy, just as the kinetic energy is the

manifestation of the translational or velocity aspect.

Our definition of work energy given above enables us to recognise its

operation in many familiar processes. Take the case of a gas at high

pressure confined in a cylinder behind a movable piston. We can at once

say that the energy of the gas is work energy because this energy may

quite clearly be transmitted from the gas by the movement of the piston.

If the latter form part of a steam-engine mechanism of rods and crank,

the energy may, by the motion of this mechanism, be transmitted to the

crank shaft, and there utilised. This is eminently a case in which

energy is _transmitted_ by matter in motion. The moving material

comprises the piston, piston-rod, and connecting-rod, which are, one and

all, endowed with both cohesive and kinetic energy qualities, and form

together the transmission machine. So long as the piston is at rest only

one aspect of the work energy of the gas is apparent, namely, the

pressure aspect, but immediately motion and transmission take place,

both aspects are presented. The work energy of the gas, obtained in the

boiler by a _transformation_ of heat energy is thus, by matter in

motion, transmitted and made available at the crank shaft. The shaft

itself is also commonly utilised for the further transmission of the

work energy applied. By the application of the energy at the crank, it

is thrown into a state of strain, and at the same time is endowed with

kinetic energy of rotation. It thus forms a machine for transmission,

and the work energy applied at one point of the shaft may be withdrawn

at another point more remote. The transmission is, in reality, effected

by the movement of the material of the shaft. So long as the shaft is

stationary, it is clear that no actual transmission can be carried out,

no matter how great may be the strain imposed. If our engine mechanism

were, by a change in design, adapted to the use of a liquid substance as

the working material instead of a gas, it is clear that no change would

be effected in the general conditions. The energy of a liquid under

pressure is again simply work energy, and it would be transmitted by the

moving mechanism in precisely the same manner.

From the foregoing, it will now be evident to the reader that the energy

originally applied to the primary mass (Sec. 3) of our cosmical system must

be work energy. It is this form of energy also which is inherent to each

unit of the planetary system associated with the primary. In this system

it is of course presented outwardly in the two phases of kinetic energy

and energy of strain or distortion. It is apparent, also, that work

energy could be transmitted from the primary mass to the separate

planets on one condition only, that is, by the movement of some material

substance connecting each planet to the primary. Since no such material

connection is admitted, the transmission of work energy is clearly

impossible.

32. _Complete Secondary Cyclical Operation_

A general outline of the conditions of working and the relationships of

secondary processes has already been given in the General Statement (Sec.

9), but it still remains to indicate, in a broad way, the general

methods whereby these operations are linked to the atmospheric machine.

In the example of the simple pendulum, it has been pointed out that the

energy processes giving rise to heating at the bearing surfaces and

transmission of energy to the air masses are not directly reversible

processes, but really form part of a more extensive cyclical operation,

in itself, however, complete and self-contained. This cyclical operation

may be regarded as a typical illustration of the manner in which

separate processes of energy transmission or transformation, such as

already described, are combined or united in a continuous chain forming

a complete whole.

It has been assumed, in all the experiments with the pendulum, that the

operating energy is initially communicated from an outside source, say

the hand of the observer. This energy is, therefore, the acting energy

which must be traced through all its various phases from its origin to

its final destination. At the outset, it may be pointed out that this

energy, applied by hand, is obtained from the original rotational energy

of the earth by certain definite energy processes. Due to the influences

of various incepting fields which emanate from the sun (Secs. 17-19), a

portion of the earth's rotational energy is transformed into that form

of plant energy which is stored in plant tissue, and which, by the

physico-chemical processes of digestion, is in turn converted into heat

and the various other forms of energy associated with the human frame.

This, then, is the origin of the energy communicated to the pendulum.

Its progress through that machine has already been described in detail

(Secs. 21-26). The transformation of energy of motion to energy of position

which takes place is in itself a reversible process and may in the

meantime be neglected. But the final result of the operations, at the

bearing surfaces and in the air masses surrounding the moving pendulum,

was shown to be, in each case, that heat energy was communicated to

these air masses. The effect of the heat energy thus impressed, is to

cause the expansion of the air and its elevation from the surface of the

earth in the lines or field of the gravitative attraction, so that this

heat energy is transformed, and resides in the air masses as energy of

position. The energy then, originally drawn from the rotational energy

of the earth, has thus worked through the pendulum machine, and is now

stored in the air masses in this form of energy of position. To make the

process complete and cyclical this energy must now, therefore, be

returned once more to the earth in its original rotational form. This

final step is carried out in the atmospheric machine (Sec. 41). In this

machine, therefore, the energy of position possessed by the air masses

is, in their descent to their original positions at lower levels,

transformed once more into axial or rotational energy. In this fashion

this series of secondary processes, involving both transformations and

transmissions, is linked to the great atmospheric process. The amount of

energy which operates through the particular chain of processes we have

described is, of course, exceedingly small, but in this or a similar

manner all secondary operations, great or small, are associated with the

atmospheric machine. Instances could readily be multiplied, but a little

reflection will show how almost every energy operation, no matter what

may be its nature, whether physical, chemical, or electrical, leads

inevitably to the communication of energy to the atmospheric air masses

and to their consequent upraisal.

It is interesting to note the infallible tendency of energy to revert

to its original form of axial energy, or energy of rotation, by means of

the air machine. All Nature bears witness to this tendency, and although

the path of energy through the maze of terrestrial transformation often

appears tortuous and uncertain, its final destination is always sure.

The secondary operations are thus interlinked into one great whole by

their association in the terrestrial energy cycle. Many of these

secondary operations are of short duration; others extend over long

periods of time. Energy, in some cases, appears to slumber, as in the

coal seams of the earth, until an appropriate stimulus is applied, when

it enters into active operation once more. The cyclical operations are

thus long or short according to the duration of their constituent

secondary energy processes. But the balance of Nature is ever preserved.

Axial energy, transformed by the working of one cyclical process, is

being as continuously returned by the simultaneous operation of others.