The usual holiday quiet has been animated by news of the discovery
that the planet Mars has two moons--that a star in the constellation
Cygnus is changing into a nebula--that Mr Stanley has made his way
down the Congo to the sea--that Sir William Thomson has invented a
chemical indicator which when attached to a sounding-line will tell the
depth without stopping the ship, and that the ancient obelisk which
has been talked about from the beginning of the present century, is
at last on its way from Egypt to England. And now the quiet time is
over; for colleges, schools, and hospitals have begun their scientific
lectures; the learned Societies are resuming their evening meetings and
discussions; the Royal Society have given notice that applications for
aid from the funds for promotion of science voted by parliament must be
sent in before December 31; and soon the men of philosophy and science
will be as busy as the men whose talk is of merchandise.
Planetary satellites are a characteristic of our solar system, and
now that the able astronomers at Washington have shewn that Mars has
two moons, that mythological deity ceases to be exceptional. Neither
in rate of motion nor in distance from the planet is there agreement
between the two; for we are informed by Mr Christie of the Greenwich
Observatory, that 'the outer satellite revolves once in less than a day
and a quarter, and the inner three and a quarter times in one day. The
phenomena,' he continues, 'presented to an inhabitant of Mars must be
very remarkable, for the outer satellite will remain above the horizon
for two and a half days and nights, and the inner will rise in the
west and set in the east twice in the course of the night. The lunar
method of determining longitudes must be singularly easy with such a
rapidly moving satellite, which is equivalent to the addition of a
minute-hand to the celestial clock, which in our case has to be read by
the hour-hand alone.'
Mr Christie tells us further that the two moons have been seen by
observers at Greenwich, Paris, and other places; and he remarks, that
if they 'have been in existence for ages, it seems strange they have
not been discovered before, especially at the opposition of 1862, when
Mars approached the earth as closely as this year; but it is naturally
much easier to see an object that has once been found than to discover
it independently. The satellites must be much smaller than any of the
minor planets hitherto discovered. Can Mars have picked up a couple of
very large meteorites, which have approached him closely?'
Leaving this question to the experts, we add, in passing from the
subject, that the orbital velocity of one of the moons is seventy-nine
miles a minute; of the other, fifty miles; and that their discovery has
enabled astronomers to determine the mass of Mars, and thus settle what
has been to them an important and long-standing problem.
As a reverse to this astronomical triumph, we have to record the death
of Le Verrier, an astronomer pre-eminent among the astronomers of the
century, with such insight and such capacity for work as have rarely
been equalled. He will be known through coming ages by his theory
of the motions of the planets, and the tables founded thereon; for
provided with these, astronomers all over the world are enabled to
carry on their work with an accuracy hitherto unapproachable, and to
widen its application. France has lost one of her greatest sons, and
Science one of her most distinguished elaborators; but he lives in
his works, and through them will continue to guide and instruct the
mariner, the astronomer, and the physicist.
Mr Stanley's exploit in turn settles an interesting geographical
question, for embarking on the Lualaba, he followed that river down
to the Congo, and the Congo down to the sea. Thus the drainage of the
lake-region of Central Africa finds its way into the Atlantic. The
voyage proved fatal to some of the party through conflict with hostile
natives, and accidents among the cataracts, which on the equator impede
navigation for a distance of thirteen miles. The river is described
as from two to ten miles wide: it drains an area of one million four
hundred thousand square miles; and now with the Congo and the Nile,
Africa may claim two of the largest rivers in the world.
It often happens in dark weather that the position of a ship can be
ascertained only by sounding; and when near the land, the soundings
should be frequent if danger is to be avoided. But as the depth cannot
be accurately measured without bringing the ship to a stand-still, the
seaman is apt to prefer risk to loss of time; and the consequence is
at times--a wreck. Sir William Thomson, to whom navigation is indebted
for an important improvement in sounding apparatus, has recently proved
by experiment that by adding thereto a chemical appliance the sounding
may be taken while the ship is in motion. This appliance consists
of a copper tube, attached to the lower end of the sounding wire,
and inclosing a slender glass tube, and a small quantity of sulphate
of iron. As the tube descends, the pressure of the water forces the
sulphate into the glass tube: it leaves a stain on the glass; and
according to the height of the stain, as indicated on a scale, such is
the depth of the water. We are informed that this ingenious instrument
has been tried on board the _Minotaur_ with satisfactory proof of its
'absolute accuracy and extreme handiness.'
H.M.S. _Téméraire_ is appropriately named, for she is big enough and
heavy enough to do battle with any antagonist that may venture to face
her in the Mediterranean, whither she is bound. The engines are 7697
horse-power. No wonder that the mighty vessel when under way pushes up
a ten-foot wave at her bow! The diameter of the principal cylinders is
seventy inches; of the crank shaft, twenty-two inches; from which an
idea may be formed of the bulk of the ponderous mass. To reduce the
weight as much as possible, wrought-iron and brass are largely used in
the construction of the engines and fittings, in place of cast-iron,
so that in the condensers there are more than eleven thousand brass
tubes, which make up a cooling surface of fourteen thousand square
feet. To assist the movements and facilitate the working of this giant
among war-ships, there are on board thirty-four small engines, thus
distributed: two turning, two starting, four feed, two circulating,
four fan, two bilge, one capstan, one steering, four pumping, four
ashes lifters, two hydraulic gear workers, one torpedo reservoir
charger, one to work the electric machine which feeds the lights on
the bridge, and four others. In all this there seems something of
complication; but we may hope that everything will work well even in
the worst of weather, so that the ship may justify her name and the
merits of her builders.
The Iron and Steel Institute held their annual meeting at
Newcastle-on-Tyne, where, and in the neighbourhood, the manufactures
and other mechanical operations abound in which the members take
most interest. That these are mines, coking furnaces, brick-works,
iron-works, and foundries, may easily be imagined. One of the papers
read shewed that cast-steel could be produced without compression, and
as readily as cast-iron; which if confirmed by further experiment, will
prove of great value in the manufacture of heavy cannon.
In a visit to Sir William Armstrong's works at Elswick, the members
saw the welding of coils for guns under the great steam-hammer, which
weighs thirty tons, and falls upon an anvil of one hundred and twenty
tons, with a stroke of twelve feet six inches; and yet so perfect is
the hydraulic moving machinery, that it can be easily worked by one
man. The four cranes too by which the ponderous masses of red-hot metal
are lifted, are 'under the command of one man, who can sling them right
and left, or move the load up or down just as he pleases without moving
from his post.' Another example of what can be done by water was shewn
at the swing-bridge across the Tyne, which has four spans of about one
hundred feet each. The portion which opens weighs fifteen hundred tons.
'The hydraulic machinery for actuating it, is contained in the hollow
pier which forms the pivot on which it turns. The pier is surmounted
by a watch-tower, in which are the levers for opening and shutting the
bridge. It takes just one minute to swing the bridge from its closed
position across the river to the open one in line with the stream.'
Mechanists have pointed out that water-engines use the same amount of
water when merely driving themselves (which is next to doing nothing)
as when exerting their entire power. If it be true that there should
be a proportion between the amount of work and the quantity of water,
this, as we are informed, is provided for by Hastie and Company of
Greenock in an invention by means of which an automatic lengthening or
shortening of the stroke of the engine takes place, in accordance with
the work to be done. No sooner does the engine become, so to speak,
aware of the demand on its power, than it immediately adapts itself
thereto without external assistance.
To revert to the Institute: A description was given of the coking
coal-field of South Durham; it is thirteen miles long by eleven miles
wide, and assists in supplying the present demand for fourteen and a
half million tons of coke yearly. At one of the collieries there used
to be a waste of three hundred tons of coal every week; but now by
means of improved coking ovens, and intercepting the waste heat, this
loss is prevented. It is found too that the large deposits of inferior
coal can be utilised, by crushing, washing, and then coking: a very
important fact, for there is in all our coal-fields a large breadth of
coal which has been hitherto rejected as worthless, but which will now
be worked and converted into coke.
A paper was read which shews that ways are opening for the utilisation
of slag: it is now converted into bricks, cement, mortar, concrete,
glass, and cotton or wool. This wool is an excellent material for
covering boilers and pipes to prevent waste of heat. Four million
bricks have been made, which looks promising.
The _Journal_ of the Institute contains descriptions of machinery
with which we may fitly supplement the foregoing: At Smethwick near
Birmingham, there is a screw-factory which, with its clever mechanical
contrivances, is something to wonder at. All the sizes of screws used
in carpentry and cabinet-making are made of iron wire chopped into
lengths, and shaped in a series of self-acting machines. A blow on one
end forms a head, which is speedily turned true in a revolving chuck,
the nick is cut by a small circular saw, a revolving jaw then seizes
the head, and the 'worm' or screw is turned in a twinkling; and in
this way half a million screws an hour are produced. This seems almost
incredible; but the screwing-shed alone covers nearly an acre and a
half, and contains two thousand machines. These being self-acting, five
or six can be kept going by one woman.
Another example from the same source shews the application of machinery
to soft goods and tailoring: At a wholesale clothing establishment in
Leeds, more than a thousand hands and three hundred sewing-machines are
employed. The cutting-out is done by means of knife-machines driven
by steam, which cut through thirty-five layers of thick or a hundred
and twenty layers of thin cloth at once, the pattern being marked
on the topmost piece. The pile, as is stated, is manipulated around
the knife-blade, just as a block of wood is moved when being cut by
a band-saw. Pressing-machines heated by gas are used in place of the
old tailor's goose, and as they are worked by a treadle, the workman's
hands are at liberty to guide the heated iron over the seams.
As our readers know, experiments with continuous brakes for railway
trains have been made in England and America. We now learn from a
published Report that similar experiments have been made in Germany,
and that generally preference is given to the Westinghouse brake. All
other things being equal, that must be the best brake which will stop
a train within the shortest distance, and that this is done by the
Westinghouse appears to be clearly established. This brake has been
adopted for the state railways by the Belgian government; and that
the question should be settled without delay is regarded as essential
in all the countries where it has been tried. The Board of Trade in
a recent Report take an unusually decided tone on this point. As the
_Times_ remarks: 'They not only constantly refer to continuous brakes
as the great railway want of the day, but they also lay down, for the
first time, the qualities which a continuous brake ought to possess.
The chief of these are instantaneous action when applied either by
driver or guard, automatic action, regular use in daily work, and
uniformity upon different lines, so that when vehicles from one line
are connected with the trains of another the same brake-power may be
available for both.' We are further informed that the Board have sent a
circular to the railway companies with intimation that the sooner the
requirements implied in the foregoing description are put into practice
the better will it be for all concerned. There is common-sense in this:
it will be read with satisfaction by all who travel by railway.
Social Science this year ventured into a high latitude, and held its
Congress at Aberdeen, where the usual endeavours were made to promote
health, wealth, and morality, which includes law. A paper read by Mr
Caird on 'Economy and Trade,' chiefly as regards agriculture, will
comfort those timid folk who are always looking for that troublous
time when all our foreign supply of 'bread-stuffs' shall be cut off.
'We grow at present,' he said, 'nearly one million acres less wheat
than we did twenty years ago. We have only to revert to the acreage of
1856 to meet such a deficiency as would be caused by all Europe being
shut against us. And beyond that, we possess in our immense breadth
of pasture-land a never-failing resource of stored-up agricultural
power, which could be at once applied to the production of corn, if
from any circumstance that course became at the same time necessary and
profitable.'
Mr Edwin Chadwick, a veteran among sanitary reformers, read papers on
Cleanliness and Health and on 'House Accommodation,' which deserve
wide diffusion and careful consideration. But it may be said of these,
as well as of many other topics brought forward for discussion, that
'it is better to be in possession of a few important principles than a
host of facts; then reflection and reason have elbow-room, and are not
hampered and brought to a dead-lock, by cramming a disorganised mass of
knowledge into the brain.'
Mr H. C. Russell, government astronomer for New South Wales, has
published a descriptive, historical, and tabular account of the
climate of that colony in an octavo volume of more than two hundred
pages, with a map and diagrams. Although the colony is not yet a
hundred years old, Mr Russell has been unable to fill up the gaps
which unfortunately exist in the record of its winds and weather; but
his book is interesting and valuable nevertheless. He discusses the
whole range of meteorological phenomena; he tells us about the hot
winds and where they come from; about thunder and hail-storms; about
lakes, floods, and tides; about droughts; about the rains, and why
they vary; and about the great swarms of moths which at times come in
clouds and infest miles of country. In his description of the physical
characteristics of New South Wales, he gives particulars which will be
quite new and perhaps surprising to many readers. 'Within the colony,'
he says, 'may be found all climates, from the cold of Kiandra, where
the thermometer sometimes falls eight degrees below zero, and frost and
snow hold everything in wintry bonds for months at a stretch, and where
upwards of eight feet of snow sometimes falls in a single month, to
the more than tropical heat and extreme dryness of our inland plains,
where frost is never seen, and the thermometer in summer often for days
together reads from one hundred to one hundred and sixteen degrees, and
sometimes in hot winds reaches one hundred and thirty degrees, and
where the average annual rainfall is only twelve to thirteen inches,
and sometimes _nil_ for a whole year.' Clearly there is more scope than
was thought for settlers who like 'bracing weather.' In discussing
the observations, Mr Russell is of opinion that a periodicity, or a
tendency to cycles of phenomena, is discoverable.
How to prevent famine, will be for some time to come a very serious
question in India; and while charity seeks to palliate the misery,
science is trying to discover the laws of the rainfall, and to devise
means of storing large supplies of water against seasons of drought.
Examples are not wanting. More than a thousand years ago one of the
kings of Ceylon erected a tank, Kanthalai, on a scale so enormous,
that were it to be built now it would cost a million sterling. This
tank is to be repaired and made available for irrigation. In another
district the tank of Kalowewa was twelve miles long and thirty miles
in circumference, inclosed by embankments sixty feet in height, and
was kept full by two rivers which flowed into it from the hills. In
the district of Manaar the Giant's tank offers a further resource, and
makes us aware of the pains taken by the natives to secure a sufficient
water-supply in former ages. If India has not tanks enough for her
wants, they must be built, for periodical famines are an opprobrium to
Christian civilisation.
As regards Ceylon, we learn from an address delivered by Sir W. H.
Gregory, the governor, that great improvements have been made in that
fertile island: jungle and swamp have been converted into rice-fields
or lakes: in Kandy there is a constant water-supply: fountains are set
up in the villages: laws are in force for preservation of the forests,
of the deer, buffalo, and elephant: the pearl-oyster, after some years'
disappearance, has returned to the shores: a breakwater is in course of
building which will convert the open roadstead of Colombo into a safe
harbour, accessible to large ships at all seasons, and it is thought
that in time Ceylon will become the great free port of the East.
Pitury is a stimulant said to be of marvellous power, and known to
be used by the aborigines of Central Australia; but its origin has
hitherto remained undiscovered. Last February, however, after vainly
endeavouring for many years to obtain a specimen of the plant, Baron
Ferdinand von Müller, Director of the Botanical Gardens at Melbourne,
succeeded in getting some leaves; and after careful microscopic
examination, he has shewn that they are derived from the _Duboisia
Hopwoodii_, which he described in 1861. This bush extends from the
Darling River and Barcoo to West Australia, through desert scrubs, but
is of exceedingly sparse occurrence anywhere. In fixing the origin of
the pitury, a wide field for further inquiry is opened up, inasmuch as
a second species of _Duboisia_, extends in the forest-lands from the
neighbourhood of Sydney to near Cape York, and has also been traced
in New Caledonia, and more recently in New Guinea. In all probability
the latter shares the properties of the former, as Baron von Müller
finds that they both have the same burning acrid taste. The natives of
Central Australia chew the leaves of the pitury, just as the Peruvians
and Chilians masticate those of the coca, to invigorate themselves
during their long foot-journeys through the deserts. Baron von Müller
is not certain whether the aborigines of all districts in which the
pitury grows are really aware of its stimulating power; but those
living near the Barcoo travel many days' journey to obtain this, to
them, precious foliage, which they always carry about with them,
broken into small fragments and tied up in little bags. The blacks
use the pitury to excite their courage in warfare, and a large dose
has the effect of infuriating them. It is by no means improbable that
experiments may shew that by this discovery a new and perhaps important
medicinal plant has been gained.