INSTRUMENTS NOT DESCRIBED IN THE PRECEDING CHAPTERS.
=145. Chemical Weather Glass.=--This curious instrument appears to have
been invented more than a hundred years ago, but the original maker is not
known. It is simply a glass vial about ten inches long and three quarters
of an inch in diameter, which is nearly filled, and hermetically sealed,
with the following mixture:--Two drachms of camphor, half a drachm of
nitrate of potassium, half a drachm of chlorate of ammonium, dissolved in
about two fluid ounces of absolute alcohol mixed with two ounces of
distilled water. All the ingredients should be as pure as possible, and
each vial filled separately. When the instruments are made in numbers and
filled from a common mixture, some get more than the due proportion of the
solid ingredients, and consequently such glasses do not exhibit that
uniformity of appearance and changes, that undoubtedly should accompany
similar influencing circumstances. It is in consequence of a want of
precision and fixed principle of manufacture, that these interesting
instruments are not properly appreciated, and more generally used.
The glass should be kept quite undisturbed, exposed to the north, and
shaded from the sun. Camphor is soluble in alcohol, but not in water,
while both water and alcohol have different solvent powers, according to
the temperature; hence, the solid ingredients being in excess for certain
conditions of solution, depending upon temperature chiefly, and perhaps
electricity and the action of light also, appear as crystals and disappear
with the various changes that occur in the weather.
The various appearances thus presented in the menstruum have been inferred
to prognosticate atmospheric changes. The following rules have been
deduced from careful study of the glass and weather:--
1. During cold weather, beautiful fern-like or feathery crystallization is
developed at the top, and sometimes even throughout the liquid. This is
the normal state of the glass during winter. The crystallization increases
with the coldness; and if the structure grows downward, the cold will
continue.
2. During warm and serene weather, the crystals dissolve, the upper and
greater part of the liquid becoming perfectly clear. This is the normal
state of the glass during summer. The less amount of crystallization, that
is, the greater the clear portion of the liquid (for there is always some
of the composition visible at the bottom), the greater the probability of
continued fine dry weather.
3. When the upper portion is clear, and flakes of the composition rise to
the top and aggregate, it is a sign of increasing wind and stormy
weather.
4. In cold weather, if the top of the liquid becomes thick and cloudy, it
denotes approaching rain.
5. In warm weather, if small crystals rise in the liquid, which still
maintains its clearness, rain may be expected.
6. Sharpness in the points and features of the fern-like structure of the
crystals, is a sign of fine weather; but when they begin to break up, and
are badly defined, unsettled weather may be expected.
Admiral FitzRoy, in _The Weather Book_, writes of this instrument as
follows:--"Since 1825, we have generally had some of these glasses, as
curiosities rather than otherwise; for nothing certain could be made of
their variations until lately, when it was fairly demonstrated that if
fixed undisturbed in free air, not exposed to radiation, fire, or sun, but
in the ordinary light of a well-ventilated room, or, _preferably_, in the
outer air, the chemical mixture in a so-called storm-glass varies in
character with the _direction_ of the wind--not its force, _specially_
(though it _may_ so vary in _appearance_, only from another cause,
_electrical tension_).
"As the atmospheric current veers toward, comes from, or is only
_approaching_ from the polar direction, this chemical mixture--if closely,
even microscopically watched--is found to grow like _fir_, _yew_, fern
leaves, or hoar-frost--or like crystallizations.
"As the wind, or great body of air, tends more from the _opposite_
quarter, the lines or spikes--all regular, hard, or crisp
features--gradually diminish, till they vanish.
"Before, and in a continued southerly wind, the mixture sinks slowly
downward in the vial, till it becomes shapeless, like melting white sugar.
"Before, or during the continuance of a northerly wind (polar current),
the crystallizations are beautiful (if the mixture is correct, the glass a
_fixture_, and duly _placed_); but the least motion of the liquid disturbs
them.
"When the main currents meet, and turn _toward the west_, making
_easterly_ winds, stars are more or less numerous, and the liquid dull, or
less clear. When, and while they _combine by the west_, making westerly
winds, the liquid is clear, and the crystallization well-defined, without
loose stars.
"While _any hard_ or _crisp_ features are visible below, above, or at the
top of the liquid (where they form for polar winds), there is _plus_
electricity in the air; a _mixture_ of polar current co-existing _in that
locality_ with the opposite, or southerly.
"When nothing but soft, melting, sugary substance is seen, the atmospheric
current (feeble or strong as it may be) is southerly with _minus_
electricity, unmixed with, and _uninfluenced_ by, the contrary wind.
"Repeated trials with a delicate galvanometer, applied to measure electric
tension in the air, have proved these facts, which are now found useful
for aiding, with the barometer and thermometer, in forecasting weather.
"Temperature affects the mixture much, but not solely; as many comparisons
of winter with summer changes of temperature have fully proved.
"A confused appearance of the mixture, with flaky spots, or stars, in
motion, and less clearness of the liquid, indicates south-easterly wind,
probably strong to a gale.
"Clearness of the liquid, with more or less perfect crystallizations,
accompanies a combination, or a contest, of the main currents, by the
_west_, and very remarkable these differences are,--the results of these
air currents acting on each other _from_ eastward, or from an entirely
opposite direction, the _west_.
"The glass should be wiped clean now and then,--and once or twice a year
the mixture should be disturbed, by inverting and gently shaking the glass
vial."
[Illustration: Fig. 93.]
=146. Leslie's Differential Thermometer.=--A glass tube having a large
bulb at each extremity, and bent twice at right angles, as represented in
figure 93, containing strong sulphuric acid tinged with carmine, and
supported at the centre by a wooden stand, constitutes the differential
thermometer as invented by Professor Leslie. The instrument is designed to
exhibit and measure small differences of temperature. Each leg of the
instrument is usually from three to six inches long, and the balls are
about four inches apart. The calibre of the legs is about 1/50 inch, not
more; the other part of the tube may be wider. The tube is filled with the
liquid, the bulbs contain air. When both bulbs are heated alike, each
scale indicates zero. The scale is divided so that the space between the
freezing and the boiling-points of water is equal to 1,000 parts. When one
bulb is heated more than the other, the difference of temperature is
delicately shown by the descent of the coloured fluid from the heated
ball. It is uninfluenced by changes in the temperature of the atmosphere;
hence it is admirably adapted for experiments of radiant heat. The theory
of the instrument is that gases expand equally for uniform increments of
heat.
=147. Rumford's Differential Thermometer= differs from that just described
in simply containing only a small bubble of liquid, which lies in the
centre of the tube, when both bulbs are similarly influenced. The bulbs
and other parts of the tube contain air. When one bulb is more heated than
the other, the bubble moves towards the one less heated; and the scale
attached to the horizontal part of the tube affords a measurement of the
difference of temperature.
[Illustration: Fig. 94.]
=148. Glaisher's Thermometer Stand.=--The thermometer stand consists of a
horizontal board as a base, of a vertical board projecting upwards from
one edge of the horizontal one, and of two parallel inclined boards,
separated from each other by blocks of three inches in thickness,
connected at the top with the vertical, and at the bottom with the
horizontal board, and the air passes freely about and between them all. To
the top of the inclined boards is connected a small projecting roof to
prevent the rain falling on the bulbs of the instrument, which are carried
on the face of the vertical board, with their bulbs projecting below it,
so that the air plays freely on the bulbs from all sides. The whole frame
revolves on an upright post firmly fixed to the ground, as shown in the
engraving, fig. 94; and in use, the inclined side is always turned towards
the sun.
=149. Thermometer Screen, for use at Sea.=--This screen, or shade, was
designed by Admiral FitzRoy, and has been in use for several years on
board H.M. vessels and many merchant-ships. It is about twenty-four inches
long by twelve wide and eight deep; having lattice-work sides, door, and
bottom; with perforation also at top, so contrived that the air has free
access to the interior, while the direct rays of the sun, rain, and sea
spray are effectually excluded from the thermometers mounted inside. There
is ample space for two thermometers placed side by side on brackets, at
least three inches from each other or any part of the exterior of the
screen. One thermometer should be fitted up as a "wet bulb" (see p. 105).
A small vessel of water can easily be fixed inside the screen so as to
retain its position and contents under the usual motions of the ship; and
by means of a piece of cotton-wick, or muslin rag tied round the bulb of
the thermometer and trailing into the cup of water, keep the bulb
constantly moist.
Self-registering thermometers should be protected by a similar screen. It
has been found that thermometric observations made at sea are not valuable
for scientific purposes unless the instruments have been duly protected by
such a screen.
=150. Anemoscope=, or Portable Wind Vane for travellers, with compass, bar
needle, &c., shows the direct course of the wind to half a point of the
compass.
[Illustration: Fig. 95.]
=151. Evaporating Dish, or Gauge= (fig. 95), for showing the amount of
evaporation from the earth's surface. This gauge consists of a brass
vessel, the area or evaporating surface of which is accurately determined;
and also a glass cylindrical measure, graduated into inches, tenths, and
hundredths of inches. In use, the evaporating gauge is nearly filled with
water, the quantity having been previously measured by means of the glass
cylinder; it is then placed out of doors, freely exposed to the action of
the atmosphere; after exposure, the water is again measured, and the
difference between the first and second measurement shows the amount of
evaporation that has taken place. If rain has fallen during the exposure
of the gauge, the quantity collected by it must be deducted from the
measured quantity; the amount is shown by the quantity of rain collected
in the rain gauge. The wire cage round the gauge is to prevent animals,
birds, &c., from drinking the water.
=152. Dr. Babington's Atmidometer=, or instrument for measuring the
evaporation from water, _ice or snow_, consists of an oblong hollow bulb
of glass or copper, beneath which and communicating with it by a
contracted neck is a second globular bulb, duly weighted with mercury or
shot. The upper bulb is surmounted by a small glass or metal stem, having
a scale graduated to grains and half-grains; on the top of which is fixed
horizontally a shallow metal pan. The bulbs are immersed in a vessel of
water having a circular hole in the cover through which the stem rises.
Distilled water is then gradually poured into the pan above, until the
zero of the stem sinks to a level with the cover of the vessel. Thus
adjusted, as the water in the pan evaporates, the stem ascends, and the
amount of evaporation is indicated in grains. This instrument affords a
means of measuring evaporation from _ice or snow_. An adjustment for
temperature is necessary.
=153. Cloud Reflector.=--At the International Exhibition 1862, Mr. J. T.
Goddard exhibited a cloud mirror, for ascertaining the direction in which
the clouds are moving.
The mirror is laid on a horizontal support near a window, and fastened so
that the point marked north may coincide with the south point of the
horizon,--the several points will consequently be reversed. The edge of a
conspicuous cloud is brought to the centre of the mirror, and the observer
keeps perfectly still until it passes off at the margin, where the true
point of the horizon _from which_ the clouds are coming can be read off.
=154. Sunshine Recorder.=--Mr. Goddard also exhibited an instrument which
he calls by this name. It works by letting the sun's rays pass through a
narrow slit, and fall on photographic paper wound round a barrel moved by
clock-work; the paper being changed daily, and the photographic impression
developed and fixed in the usual manner.[19]
155. SET OF PORTABLE INSTRUMENTS.
In a small box, 8 in. by 8 in. by 4 in., a complete set of meteorological
instruments have been packed. The lid of the box, by an ingenious
arrangement, is made to take off and hang up; on it are permanently fixed
for observation, a maximum and minimum, and a pair of dry and wet bulb
thermometers. The interior of the box contains a maximum thermometer in
vacuo for solar radiation, and a minimum for terrestrial purposes, one of
Negretti and Zambra's small pocket aneroid barometers, pedometer for
measuring distances, pocket compass, clinometer, and lastly a rain gauge.
This latter instrument consists of an accurately turned brass ring having
an india rubber body fastened to it to receive the rain, which is measured
off by a small graduated glass, also contained in the box. Gentlemen
travelling will find this compact observatory all that can be desired for
meteorological observations.
156. IMPLEMENTS.
The practical meteorologist will find the following articles very useful,
if not necessary. They scarcely require description; an enumeration will
therefore suffice:--_Weather Diagrams_, or prepared printed and ruled
forms, whereon to exhibit graphically the readings of the various
instruments to render their indications useful in foretelling weather,
&c.;--_Meteorological Registers_, or Record Books, for recording all
observations, and the deductions;--_Cloud Pictures_, by which the clouds
can be readily referred to their particular classification, very necessary
to the inexperienced and learners;--Cyclone Glasses, or Horns, outline
Maps with Wind-markers, are also useful, especially in forecasting
weather.
157. HYDROMETER.
A simple kind of hydrometer is very much used at sea, as "a sea-water
test;" and as the observations are usually recorded in a meteorological
register or the ship's log-book, it may not be altogether out of place to
give a description of it here.
[Illustration: Fig. 96.]
[Illustration: Fig. 97.]
It is constructed of glass. If made of brass, the corrosive action of
salt-water soon renders the instrument erroneous in its indications. The
shapes usually given to the instruments are shown in figs. 96 and 97. A
globular bulb is blown, and partly filled with mercury or small shot, to
make the instrument float steadily in a vertical position. From the neck
of the bulb the glass is expanded into an oval or a cylindrical shape, to
give the instrument sufficient volume for flotation; finally, it is
tapered off to a narrow upright stem which encloses an ivory scale, and is
closed at the top. The divisions on the scale read downward, so as to
measure the length of the stem which stands above the surface of any
liquid in which the hydrometer is floated. The denser the fluid, the
higher will the instrument rise; the rarer, the lower it will sink.
The indications depend upon the hydrostatic principle, that floating
bodies displace a quantity of the fluid which sustains them equal to their
own weight. According, therefore, as the specific gravities of fluids
differ from each other, so will vary the quantities of the fluids
displaced by the same body when floated successively in each.
The specific gravity of distilled water, at the temperature of 62 deg. _F_,
being taken as unity, the depth to which the instrument sinks when gently
immersed in such water is the zero of the scale. The graduations extend
from 0 to 40; the latter being the mark which will be level with the
surface when the instrument is placed in water, the specific gravity of
which is 1.040. In recording observations, the last two figures
only--being the figures on the scale--are written down. Sea-water usually
ranges from 1.020 to 1.036.
A small tin, copper, or glass cylinder is useful for containing the water
to be tested. It should be wider than the hydrometer, and always filled to
the brim. If fitted to a stand, which is supported by gimbals, it will be
very convenient. Water in a bucket, basin, or other wide vessel, acquires
motion at sea, and the eye cannot be brought low enough (on account of the
edges) to read off the scale accurately.
Errors of observation may occur with the hydrometer, if it be put into
water without being clean, or without being carefully wiped. The
instrument is extremely accurate if correctly used. It should be kept free
from contact with the sides of the vessel; and all dust, smears, or
greasiness, should be scrupulously avoided, by carefully wiping it with a
clean cloth before and after use.
Whenever the temperature of the water tested differs from 62 deg., a
correction to the reading is necessary, for the expansion or contraction
of the glass, as well as the water itself, in order to reduce all
observations to one generally adopted standard.
Negretti and Zambra's hydrometer, with thermometer in the stem, shows the
density and temperature in one instrument.
For the following Tables we are indebted to the kindness of Admiral
FitzRoy:--
TABLE for reducing observations made with a BRASS HYDROMETER, assuming the
linear expansion of brass to be 0.000009555 for 1 deg. F. The correction is
additive for all temperatures above 62 deg., and subtractive for temperatures
below 62 deg.
+----------------------------------------------------------------------+
|_t deg._|Correction.||_t deg._|Correction.||_t deg._|Correction.||_t deg._|Correction.|
|----+-----------++----+-----------++----+-----------++----+-----------|
| 32 | -0.0014 || 48 | -0.0010 || 64 | +0.0002 || 80 | +0.0020 |
| 33 | .0014 || 49 | .0009 || 65 | .0003 || 81 | .0021 |
| 34 | .0014 || 50 | .0009 || 66 | .0004 || 82 | .0023 |
| 35 | .0014 || 51 | -0.0008 || 67 | .0005 || 83 | .0024 |
| 36 | .0014 || 52 | .0008 || 68 | +0.0006 || 84 | .0026 |
| 37 | .0014 || 53 | .0007 || 69 | .0007 || 85 | +0.0027 |
| 38 | -0.0014 || 54 | .0006 || 70 | .0008 || 86 | .0029 |
| 39 | .0013 || 55 | .0006 || 71 | .0009 || 87 | .0030 |
| 40 | .0013 || 56 | -0.0005 || 72 | .0010 || 88 | .0032 |
| 41 | .0013 || 57 | .0004 || 73 | .0011 || 89 | .0033 |
| 42 | .0013 || 58 | .0003 || 74 | +0.0013 || 90 | +0.0035 |
| 43 | .0012 || 59 | .0003 || 75 | .0014 || 91 | .0036 |
| 44 | -0.0012 || 60 | .0002 || 76 | .0015 || 92 | .0038 |
| 45 | .0011 || 61 | -0.0001 || 77 | .0016 || 93 | .0040 |
| 46 | .0011 || 62 | 0.0000 || 78 | .0018 || 94 | .0041 |
| 47 | -0.0010 || 63 | +0.0001 || 79 | +0.0019 || 95 | +0.0043 |
+----------------------------------------------------------------------+
TABLE for reducing observations made with a GLASS HYDROMETER, assuming the
linear expansion of glass to be 0.00000463 for 1 deg. F. The correction is
additive for temperatures above 62 deg., and subtractive for temperatures
below 62 deg.
+----------------------------------------------------------------------+
|_t deg._|Correction.||_t deg._|Correction.||_t deg._|Correction.||_t deg._|Correction.|
|----+-----------++----+-----------++----+-----------++----+-----------|
| 32 | -0.0019 || 48 | -0.0012 || 64 | +0.0002 || 80 | +0.0023 |
| 33 | .0019 || 49 | .0011 || 65 | .0003 || 81 | .0024 |
| 34 | .0018 || 50 | .0011 || 66 | .0004 || 82 | .0026 |
| 35 | .0018 || 51 | -0.0010 || 67 | .0005 || 83 | .0027 |
| 36 | .0018 || 52 | .0009 || 68 | +0.0007 || 84 | .0029 |
| 37 | .0017 || 53 | .0008 || 69 | .0008 || 85 | +0.0031 |
| 38 | -0.0017 || 54 | .0008 || 70 | .0009 || 86 | .0032 |
| 39 | .0017 || 55 | .0007 || 71 | .0010 || 87 | .0034 |
| 40 | .0016 || 56 | -0.0006 || 72 | .0012 || 88 | .0036 |
| 41 | .0016 || 57 | .0005 || 73 | .0013 || 89 | .0037 |
| 42 | .0015 || 58 | .0004 || 74 | +0.0014 || 90 | +0.0039 |
| 43 | .0015 || 59 | .0003 || 75 | .0016 || 91 | .0041 |
| 44 | -0.0014 || 60 | .0002 || 76 | .0017 || 92 | .0042 |
| 45 | .0014 || 61 | -0.0001 || 77 | .0018 || 93 | .0044 |
| 46 | .0013 || 62 | 0.0000 || 78 | .0020 || 94 | .0046 |
| 47 | -0.0013 || 63 | +0.0001 || 79 | +0.0021 || 95 | +0.0048 |
+----------------------------------------------------------------------+
158. NEWMAN'S SELF-REGISTERING TIDE-GAUGE.
At places where the phenomena of the tides are of much maritime
importance, a continuous series of observations upon the rise and fall,
and times of change, is essentially necessary as a basis for the
construction of good tide tables; and as such observations should also be
accompanied with the registration of atmospheric phenomena, we have no
hesitation in inserting a description of an accurate self-registering
tide-gauge.
The tide-gauge, as shown in the illustration, consists of a cylinder, _A_,
which is made to revolve on its axis once in twenty-four hours by the
action of the clock, _B_. A chain, to which is attached the float, _D_,
passes over the wheel, _C_, and on the axis of this wheel, _C_ (in about
the middle of it) is a small toothed wheel, placed so as to be in contact
with a larger toothed wheel carrying a cylinder, _E_, over which passes
another smaller chain. This chain, passing along the upper surface of the
cylinder, _A_, and round a second cylinder, _F_, at its further end, is
acted on by a spring so as to be kept in a constant state of tension. In
the middle of this chain a small tube is fixed for carrying a pencil,
which, being gently pressed down by means of a small weight on the top of
it, performs the duty of marking on paper placed round the cylinder the
progress of the rise or fall of the tide as the cylinder revolves, and as
it is drawn by the chain forward or backward by the rise or fall of the
float. The paper is prepared with lines equidistant from each other, to
correspond with the hours of the clock, crossed by others showing the
number of feet of rise and fall.
[Illustration]
The cylinder while in action revolves from left to right to a spectator
facing the clock, and the pencil is carried horizontally along the top of
the cylinder; and the large wheel being made to revolve by the rise and
fall of the float, turns the wheel with the small cylinder, _E_,
attached to it. If the tide is _falling_, the small chain is wound round
the cylinder, _E_, and the pencil is drawn towards the large wheel; but if
the tide is _rising_, the small chain is wound on to the cylinder, _F_, by
means of the spring contained in it, which constantly keeps it in a state
of tension. Thus, by means of the rise and fall of the tide, a lateral
progress is given to the pencil, while the cylinder is made to revolve on
its axis by the clock, so that a line is traced on the paper showing the
exact state of the tide continuously, without further attention than is
necessary to change the paper once every day, and to keep the pencil
carefully pointed; or a metallic pencil may be used, which will require
little, if any, attention.
A good self-registering tide-gauge is a valuable and important acquisition
wherever tidal observations are required, and the only perfectly efficient
instrument of this kind is that invented by the late Mr. John Newman, of
Regent Street, London. It is now in action in several parts of the world,
silently and _faithfully_ performing its duty, requiring no other kind of
attention than that of a few minutes daily, and thus admitting the
employment of the person on any other service whose duty it would
otherwise have been to have registered the tide. It has done much by its
faithful records in contributing to the construction of good tide tables
for many places; for those unavoidable defects dependent on merely
watching the surface on a divided scale are set aside by it, all erroneous
conclusions excluded, and a true delineation of Nature's own making is
preserved by it for the theorist.
ADDENDA.
1. French barometers are graduated to millimetres. An English inch is
equal to 25.39954 millimetres. Hence, 30 inches on the English barometer
scales correspond to 762 millimetres on the French barometer scales.
Conversions from one scale to another can be effected by the following
formulae:--
(1) Inches = millimetres divided by 25.39954
(2) Millimetres = inches multiplied by 25.39954
Of course, a table of equivalent values should be drawn up and employed,
when a large number of observations are to be converted from one scale to
the other.
2. In Germany, barometers are sometimes graduated with old French inches
and lines,--the vernier generally indicating the tenth of a line.
OLD FRENCH LINEAL MEASURE.
English Inches.
1 douzieme, or point = 0.0074
12 points = 1 ligne = 0.0888
12 lignes = 1 pouce = 1.065765
12 pouces = 1 pied = 12.7892
1 pied = 324.7 millimetres.
"The Germans indicate inches by putting two accents after the number;
lines, by putting three accents; 27" 3'''.85, means 27 inches 3 lines 85
hundredths of a line; more frequently, they give the height in lines, and
the preceding number becomes 327'''.85."--_Kaemtz._
3. _Rule for finding Diameter of Bore of a Barometer Tube._
"If the maker has not taken care to measure the interior diameter
directly, it may be deduced from the exterior diameter. The exterior
diameter is first measured by calipers, and, by deducting from this
diameter 0.1 of an inch for tubes from .3 to .5 of an inch in external
diameter, we have an approximation to the interior diameter of the
tube."--_Kaemtz._
4. WIND SCALES.
Sea Scale. Wind. Land Scale.
---------- ----- -----------
0 to 3 = Light = 0 to 1
3 " 5 = Moderate = 1 " 2
5 " 7 = Fresh = 2 " 3
7 " 8 = Strong = 3 " 4
8 " 10 = Heavy = 4 " 5
10 " 12 = Violent = 5 " 6
Pressure in Velocity in
Pounds (Land Scale). Miles
(Avoirdupois) (Hourly).
------------- --------- -----------
1/2 = 1 = 10
5 = 2 = 32
10 = 3 = 45
21 = 4 = 65
26 = 5 = 72
32 = 6 = 80
5. Letters to Denote the State of the Weather.
_b_ denotes blue sky, whether with clear or hazy atmosphere.
_c_ " cloudy, that is detached opening clouds.
_d_ " drizzling rain.
_f_ " fog.
_h_ " hail.
_l_ " lightning.
_m_ " misty, or hazy so as to interrupt the view.
_o_ " overcast, gloomy, dull.
_p_ " passing showers.
_q_ " squally.
_r_ " rain.
_s_ " snow.
_t_ " thunder.
_u_ " ugly, threatening appearance of sky.
_v_ " unusual visibility of distant objects.
_w_ " wet, that is dew.
A letter repeated denotes much, as _r r_, heavy rain; _f f_, dense fog;
and a figure attached denotes duration in hours, as 14 _r_, 14 hours rain.
By the combination of these letters, all the ordinary phenomena of the
weather may be recorded with certainty and brevity.
EXAMPLES.--_b c_, blue sky with less proportion of cloud. 2 _r r l l t_,
heavy rain for two hours, with much lightning, and some thunder.
The above methods of recording the force of wind and state of weather
were originally proposed by Admiral Sir Francis Beaufort. They are now in
general use at sea, and by many observers on land.
6. Table of Expansion by Heat from 32 deg. to 212 deg. F.
Platinum 0.0008842 of the length.
Glass, Flint 0.0008117 "
" with Lead 0.0008622 "
Brass 0.0018708 "
Mercury 0.0180180 "
Water 0.0433200, from 39 deg. to 212 deg.
Alcohol 0.1100 " 32 deg. to 174 deg.
Nitric Acid 0.1100
Sulphuric Acid 0.0600
7. Table of Specific Gravity of Bodies at 32 deg. F. except water, which is
taken at 39 deg.4.
Water 1.000
Alcohol, pure 0.791
" proof 0.916
Mercury 13.596
Glass 3 to 2.7
Brass 7.8 to 8.54
Platinum 21 to 22.00
Weight of a cubic foot of water, at the temperature of comparison, 62.425
lbs. avoirdupois.
The pound avoirdupois contains 7,000 grains.
Air is 813.67 times lighter than water.
The linear expansions are the mean values of the results of various
experimentalists. The specific gravities are as given in Professor
Rankine's _Applied Mechanics_.
8. Important Temperatures. Under the circumstances of--
deg.
Water boiling at 212
Mercury boils at 660
Sulphuric Acid " 590
Oil of Turpentine " 560
Nitric Acid " 242
Alcohol " 174
A Saturated Solution of Salt " 218
Vital Heat 96
Olive Oil begins to solidify 36
Fresh Water freezes 32
Sea Water freezes 28
Mercury freezes -39
9. TABLE OF METEOROLOGICAL ELEMENTS, FORMING EXPONENTS OF THE CLIMATE OF
LONDON.
--------------------------------------------------------------------+
1841 |Mean Height of Barometer, reduced to 32 deg. F., at the mean |
to | sea-level. |
1861. | +--------------------------------------------------|
| |Mean Monthly Range of Barometer. |
Months. | | +---------------------------------------------|
| | |Mean of all the Highest Temperatures. |
| | | +----------------------------------------|
| | | |Mean of all the Lowest Temperatures. |
| | | | +-----------------------------------|
| | | | |Mean Temperature. |
| | | | | +------------------------------|
| | | | | |Mean Temperature of Dew-point.|
| | | | | | +-------------------------|
| | | | | | |Mean Degree of Humidity. |
| | | | | | | +----------------------|
| | | | | | | |Mean Number of Rainy |
| | | | | | | | Days. |
| | | | | | | | +------------------|
| | | | | | | | |Average Rainfall. |
| | | | | | | | | +-------------|
| | | | | | | | | |Average |
| | | | | | | | | |Amount of |
| | | | | | | | | |Cloud (10= |
| | | | | | | | | | overcast). |
| | | | | | | | | | +---------|
| | | | | | | | | | |Prevalent|
| | | | | | | | | | |Winds. |
---------+-------+----+----+----+----+----+--+---+----+---+---------+
|Inches.| In.| deg. | deg. | deg. | deg. | | | In.| | |
---------+-------+----+----+----+----+----+--+---+----+---+---------+
January | 29.932|1.44|43.2|33.7|38.3|35.4|89| 11| 1.8|7.7|W. to N. |
| | | | | | | | | | | |
February | 29.962|1.22|44.7|33.2|38.4|34.4|85| 10| 1.6|7.4|S. to W. |
| | | | | | | | | | | |
March | 29.967|1.23|50.0|35.3|41.7|36.4|82| 10| 1.5|6.6|N. to E. |
| | | | | | | | | | | |
| | | | | | | | | | | |
April | 29.907|1.06|56.8|38.6|46.3|39.9|79| 11| 1.8|6.1|N. to E. |
| | | | | | | | | | | |
May | 29.931|1.02|64.4|44.2|52.8|45.5|76| 11| 2.1|6.1|S. to W. |
| | | | | | | | | | | |
June | 29.960|0.89|71.2|50.2|59.2|50.8|74| 11| 1.9|6.1|W. to N. |
| | | | | | | | | | | |
July | 29.970|0.79|73.8|53.2|61.9|53.9|76| 11| 2.7|6.9|W. to N. |
| | | | | | | | | | | |
August | 29.954|0.97|72.8|53.4|61.3|54.1|77| 11| 2.4|6.5|W. to N. |
| | | | | | | | | | | |
September| 29.997|0.95|67.4|48.9|56.9|51.1|81| 12| 2.4|5.9|S. to W. |
| | | | | | | | | | | |
October | 29.860|1.33|58.3|43.7|50.2|46.0|87| 13| 2.8|6.9|S. to W. |
| | | | | | | | | | | |
November | 29.929|1.53|49.3|37.7|43.4|40.1|89| 12| 2.4|7.2| S.W. |
| | | | | | | | | | | |
December | 29.979|1.52|45.0|35.5|40.1|36.9|89| 12| 1.9|7.4| W. |
| | | | | | | | | | | |
---------+-------+----+----+----+----+----+--+---+----+---+---------+
Year | 29.946|1.16|58.0|42.3|49.2|43.7|82|133|25.3|6.7| -- |
---------+-------+----+----+----+----+----+--+---+----+---+---------+
1 2 3 4 5 6 7 8 9 10 11
---------------------------------------------------------------------
+-----------------------------------------------------+
|Sun above the Horizon on Middle Day. |
| +---------------------------------------------|
| |REMARKS. |
---------+-------+---------------------------------------------|
| Hours.| |
---------+-------+---------------------------------------------|
January | 8-1/2|The majority of the nights are frosty. |
| | |
February | 10 |10 frosty nights on the average. |
| | |
March | 12 |12 ditto ditto ditto. |
| | Strong winds. |
| | |
April | 14 | 6 ditto ditto ditto. |
| | |
May | 15-1/2|Very rarely frost. |
| | |
June | 16-1/2|Sun attains greatest North Declination, 21st.|
| | |
July | 16 | |
| | |
August | 14-1/2| |
| | |
September| 12-1/2| |
| | |
October | 10-1/2|A few frosty nights. Heavy gales. |
| | |
November | 9 | 11 nights frosty. |
| | |
December | 8 |Sun attains greatest South Declination, 21st.|
| | |
---------+-------+---------------------------------------------|
Year | -- | |
---------+-------+---------------------------------------------|
12 13 |
---------------------------------------------------------------+
In the above Table, columns 1 to 10 are results obtained at the Royal
Observatory, Greenwich, by J. Glaisher, Esq., F.R.S. The data contained in
columns 2 and 10, are deduced from observations extending over the years
1841 to 1855 inclusive, and are copied from Edward Hughes' _Third Reading
Book_; the other columns are results of observations made during the
twenty years ending 1861. The rest of the information is from Luke
Howard's _Climate of London_.
These valuable data indicate the characteristics of the weather in each
month in the suburbs of London, and will be found tolerably accurate as
indications of weather, and serviceable as standards for comparisons of
observed results, at most places in England.
STANDARD WORKS ON METEOROLOGY
SUPPLIED BY NEGRETTI & ZAMBRA.
THE WEATHER BOOK: A MANUAL OF PRACTICAL METEOROLOGY.
By Vice-Admiral FITZROY, F.R.S., M.I.F., &c.
_Price_, L0 15 6
THE LAW OF STORMS,
By H. W. DOVE, F.R.S.
Translated by R. H. SCOTT, M.A.
_Price_, L0 10 6
L. F. KAEMTZ'S "COMPLETE COURSE OF METEOROLOGY,"
Translated by C. V. WALKER, Esq.
_Price_, L0 12 6
PRACTICAL METEOROLOGY,
By JOHN DREW, Ph.D., F.R.A.S.
_Price_, L0 5 0
HYGROMETRICAL TABLES,
Adapted to the use of the Wet and Dry Bulb Thermometer,
By JAMES GLAISHER, Esq., F.R.S.
_Price_, L0 2 6
TABLES OF THE CORRECTIONS FOR TEMPERATURES,
To reduce observations to the 32 deg. Fahrenheit, for Barometers with brass
scales extending from the cistern to the top of the mercurial column,
By JAMES GLAISHER, Esq., F.R.S.
_Price_, L0 1 0
TABLE OF THE DIURNAL RANGE OF THE BAROMETER,
By JAMES GLAISHER, Esq., F.R.S.
_Price_, L0 0 6
TABLES FOR CALCULATION OF HEIGHTS FROM OBSERVATIONS
ON THE BOILING-POINT OF WATER,
Adapted to the use of Negretti and Zambra's Boiling-point Apparatus.
_Price_, L0 1 0
A THERMOMETRICAL TABLE,
ON THE SCALES OF FAHRENHEIT, REAUMUR, AND CENTIGRADE,
By ALFRED S. TAYLOR, Esq., M.D., &c.
_Price_, in Sheet, with explanatory Pamphlet, L0 1 6
METEOROLOGICAL TABLES,
For the reduction of Barometrical and Hygrometrical Observations,
Determination of Heights by the Barometer and Boiling-point
Thermometer, &c.
By G. HARVEY SIMMONDS, M.B.M.S.
_Price_, L0 2 6
BAROMETER MANUAL,
Compiled by Vice-Admiral FITZROY, F.R.S.,
For the Board of Trade.
_Price_, L0 0 6
POCKET METEOROLOGICAL REGISTER AND NOTE-BOOK,
With Diagrams for exhibiting the Fluctuations of Barometer, &c.
Printed on metallic paper. _Price_, with Pencil, L0 3 0
LONDON:
PRINTED BY STRAHAN AND WILLIAMS,
7 LAWRENCE LAND, CHEAPSIDE, E.C.
NEGRETTI & ZAMBRA'S
PATENT RECORDING AND DEEP-SEA THERMOMETER.[20]
This Thermometer differs from all other Registering or Recording
Thermometers in the following important particulars:--
I. The Thermometer contains only Mercury without any admixture of Alcohol
or other fluid.
II. It has no indices or springs, and its indications are by the column of
Mercury only.
III. It can be carried in any position, and cannot possibly be put out of
order except by actual breakage of the instrument.
And lastly, it will indicate and record the exact temperature at any hour
of the day or night, or the exact temperature at any depth of the sea,
irrespective of either warm or cold currents, or stratum through which the
Thermometer may have to pass in its descent or ascent, this last very
special quality renders this Thermometer superior for deep-sea
temperatures to any others; for those now being used in the "Challenger"
sounding expedition are liable to give erroneous indications owing to
their indices slipping, and otherwise getting deranged--(This was proved
by Messrs. Negretti and Zambra at a Meeting of the British Meteorological
Society,) and _under certain conditions of temperature_ it is not possible
by the old Thermometers to obtain true temperatures at certain depths
which might be required. _Annexed is a copy of a report to the Admiralty
from Captain G. S. Nares, of H.M.S. "Challenger," dated Melbourne, March
25th, 1874, which we have taken from NATURE, July 30th, 1874, proving
the assertion._
"In the report to the Admiralty of Capt. G. S. Nares, of H.M.S.
_Challenger_ dated Melbourne, March 25, 1874, Capt. Nares, speaking of the
temperature of the ocean, especially near the pack edge of the ice,
says:--'At a short distance from the pack, the surface water rose to 32 deg.,
but at a depth of 40 fathoms we always found the temperature to be 29 deg.;
this continued to 300 fathoms, the depth in which most of the icebergs
float, after which there is a stratum of slightly warmer water of 33 deg. or
34 deg. As the thermometers had to pass through these two belts of water
before reaching the bottom, the indices registered those temperatures, and
it was impossible to obtain the exact temperature of the bottom whilst
near the ice, but the observations made in lower latitudes show that it is
about 31 deg. More exact results could not have been obtained even had Mr.
Siemens's apparatus been on board.' It seems to us that the difficulty
mentioned is one which would certainly have been surmounted by Messrs.
Negretti and Zambra's new Recording Thermometers, a description of which
appeared in NATURE, vol. ix. p. 387; this being exactly one of the cases
to which this instrument is peculiarly adapted. We believe the inventors
and makers have greatly improved their Thermometer since our description
appeared, and no doubt means will be taken by the Admiralty to transmit
one to the _Challenger_."
DESCRIPTION OF THE DEEP-SEA RECORDING THERMOMETER.
In the first place, it must be observed that the bulb of the Thermometer
is protected so as to resist the pressure of the ocean, which varies
according to depth that of three thousand fathoms being something like
three tons pressure on the square inch. The manner of protecting the bulb
was invented by Messrs. Negretti and Zambra in 1857, and has been latterly
copied by other persons and brought out as a new invention. The manner of
protecting the bulb has been described by the late Admiral R. FitzRoy, in
the first number of Meteorological Papers, page 55, published July 5th,
1857, as follows:
"Referring to the erroneous readings of all thermometers, consequent
on their delicate bulbs being compressed by the great pressure of the
ocean, he says:--'With a view to obviate this failing, Messrs.
Negretti and Zambra undertook to make a case for the weak bulbs, which
should transmit temperature, but resist pressure. Accordingly a tube
of thick glass is sealed outside the delicate bulb, between which and
the casing is a space all round, which is nearly filled with mercury.
The small space not so filled is a vacuum, into which the mercury can
be expanded, or forced by heat or mechanical compression, without
doing injury to or even compressing the inner or much more delicate
bulb.'"
[Illustration: Fig. 1.]
The construction of this instrument for deep-sea temperatures is as
follows:--
In shape it is like a syphon with parallel legs, all in one piece and
having a continuous communication, as in the annexed figure. The scale
of the Thermometer is pivoted on a centre and being attached in a
perpendicular position to a simple apparatus (which will be presently
described), is lowered to any depth that may be desired. In its
descent the Thermometer acts as an ordinary instrument, the mercury
rising or falling according to the temperature of the stratum through
which it passes; but so soon as the descent ceases, and a reverse
motion is given to the line, so as to pull the Thermometer towards the
surface, the instrument turns once on its centre, first bulb
uppermost, and afterwards bulb downwards. This causes the mercury,
which was in the left-hand column, first to pass into the dilated
syphon bend at the top, and thence into the right-hand tube, where it
remains, indicating on a graduated scale the exact temperature at the
time it was turned over. The woodcut, Fig. 1, shows the position of
the mercury _after_ the instrument has been thus turned on its centre.
A is the bulb; B the outer coating or protecting cylinder; C is the
space of rarefied air, which is reduced if the outer casing be
compressed; D is a small glass plug on the principle of Negretti and
Zambra's Patent Maximum Thermometer, which cuts off, in the moment of
turning, the mercury in the tube from that of the bulb, thereby
ensuring that none but the mercury in the tube can be transferred into
the indicating column; E is an enlargement made in the bend so as to
enable the mercury to pass quickly from one tube to another in
revolving; and F is the indicating tube or Thermometer proper. In its
action, as soon as the Thermometer is put in motion, and immediately
the tube has acquired a slightly oblique position, the mercury breaks
off at the point D, runs into the curved and enlarged portion E, and
eventually falls into the tube F when this tube resumes its original
perpendicular position.
The contrivance for turning the Thermometer over may be described as a
frame with a vertical propeller; to this frame the instrument is pivoted.
On its descent through the water the propeller is lifted out of gear and
revolves freely on its axis; but so soon as the instrument is pulled
towards the surface the propeller falls into gear and revolves in the
contrary direction, turning the Thermometer over once, and then becoming
locked and immovable.
_Directions for adjusting the Thermometer previous to its being lowered in
the Sea._
I. The mercury must all be in the left-hand column.
II. The short peg at the back of the thermometer must be in front of
the stop plate S +; in order to effect this, pull the knob which stops
the Thermometer, and slightly turn the propeller, to make the
Thermometer advance sufficiently to escape the stop plate.
Negretti & Zambra's Patent Atmospheric Recording Thermometer, Fig. 3,
differs from the Deep-sea Thermometer by its not having the double or
protected bulb, it not being required for resisting pressures. In this
case the instrument is turned over by a simple clock movement, which can
be set to any hour it may be desirable; the Thermometer is fixed on the
clock, and when the hand arrives at the hour determined upon, and to which
the clock is set as in setting an alarum clock, a spring is released and
the Thermometer turns over as before described.
[Illustration: Fig. 2.]
[Illustration: Fig. 3.]
Messrs. Negretti and Zambra have arranged a Wet and Dry Bulb Hygrometer
upon the same plan.
NEGRETTI & ZAMBRA'S PRICE LIST OF STANDARD METEOROLOGICAL AND OTHER
PHILOSOPHICAL INSTRUMENTS.
_The marginal figures in this List and the numbers of the wood engravings
refer to paragraphs in "Negretti & Zambra's Treatise on Meteorological
Instruments."_
L s. d.
4 =Standard Barometers=, Fortin's arrangement, as Fig. 3
with mahogany board 8 8 0
Ditto ditto with Millemetre and English scales 9 9 0
Ditto ditto with tube, 0.45 internal diameter and
millimetre scale 10 10 0
=Observatory Standard Barometers=, extra large tubes and
cisterns L25 0 0 35 0 0
Ditto ditto arranged for observations being taken
by the Cathetometer 18 18 0
=Cathetometer=, for use with above 21 0 0
9 =Self Compensating Standard Barometer=, Fig. 6 20 0 0
10 =Standard Barometer=, with electrical adjustment 15 15 0
11 =Pediment Barometers=, Fig 7 L1 1 0 2 2 0
Ditto ditto Fig. 8 L3 3 0 3 10 0
Ditto ditto Fig. 9 L4 10 0 5 10 0
Ditto ditto Fig. 10 8 10 0
Ditto ditto ditto handsome carved mountings,
in mahogany, oak, or walnut wood L8 8 0 L10 10 0 12 12 0
14 =FitzRoy's Storm or Sea Coast Fishery Barometer=, Fig. 12 5 5 0
Ditto ditto with two verniers 6 6 0
Ditto ditto mounted in ornamental carved frames, oak,
walnut, or mahogany L6 10 0 8 8 0
19 =Marine Barometers=, ordinary forms, Figs. 13 and 14
L2 2s. L2 10s. 3 3 0
Ditto ditto Best mounted L5 5s. 6 6 0
20 =The Board of Trade or Kew Marine Barometer=, Fig. 15,
L4 4s. L5 5s. 6 6 0
22 =Negretti and Zambra's FitzRoy Marine or Gun Barometer=,
Fig. 16, with N. and Z.'s Patent Porcelain Scales, as
used in Her Majesty's Navy 5 10 0
Extra Tube for ditto 1 15 0
25 =Negretti and Zambra's Farmer's Barometer or Domestic
Weather Glass=, Fig. 17 2 10 0
28 =Negretti and Zambra's Miner's Barometers=
L1 1s. L2 2s. 3 3 0
31 =Dial or Wheel Barometers=, Figs. 18, 19, 20, 21
L3 3s. L4 4s. 5 5 0
Ditto ditto in carved ornamental mountings
L5 10s. L6 6s. L8 8s. 10 10 0
Ditto ditto rosewood, inlaid with pearl or metal. Made
to order, Figs. 22 and 23. Price varying with size, &c.
37 =Gay Lussac's Syphon Tube Mountain Barometer= L6 6 0 8 8 0
32 =Standard Syphon Barometer=, Gay Lussac's arrangement,
Fig. 24 5 5 0
38 =Negretti and Zambra's Standard Mountain Barometer=, with
Fortin's cistern, with tripod stand and travelling case,
Fig. 30 10 10 0
34 =Barograph, or Self-registering Barometer=, with syphon
mercurial tube. Negretti and Zambra's improved arrangement,
Fig. 26 18 18 0 25 0 0
=Negretti and Zambra's Self-recording Aneroid Barometer=,
with =Clock= 22 0 0
48. =ANEROID BAROMETERS.=
=Aneroid Barometers,= with card dials 4-1/2 inches diameter,
best quality. 2 10 0
Ditto ditto with silvered metal dial 3 0 0
Ditto ditto with ditto and thermometer 3 10 0
Ditto ditto ditto with corrected scale, as
supplied by Negretti and Zambra to the Royal Navy 5 5 0
=Aneroid Barometers=, with elegantly-chased dials 4 4 0
Ditto ditto with raised ring on dial 5 5 0
Ditto ditto ditto with thermometer 6 6 0
=Aneroid Barometer=, for altitude measurements with revolving
ring, carrying index, range of scale 20,000 feet 4-1/2 inches
diameter, with magnifier 8 8 0
=POCKET ANEROID BAROMETERS.= Fig. 34.
49 =Pocket Aneroid Barometer=, 2-3/4 inches diameter, with
silvered metal scale 3 3 0
Ditto ditto for measuring altitudes to 10,000 feet
compensated for temperature, in leather case 5 5 0
Ditto ditto ditto to 20,000 feet, with magnifier 6 6 0
50 =WATCH-SIZE ANEROID BAROMETERS= in gilt metal cases (see figure 35.)
=Watch-Size Aneroid Barometer=, weather range L3 3 0 4 4 0
Ditto ditto of best construction, extra thin, for
meteorological observations or altitude measurements to
10,000 feet 5 5 0
Ditto ditto ditto to 20,000 feet, compensated for
temperature 6 6 0
Either of the above Watch-size Barometers may be had in Stout
Silver Cases at a cost of L2 2s. extra
_Watch-size Aneroid Barometers in Solid Gold, highly-finished cases.
L15 15s. to L21._
Table Stands for Aneroid Barometers of Carved Oak or other woods,
10s. 6d., 25s., 35s., to L5 5s.
=Ships' Aneroid Barometers=, in suitable mountings L2 10s. L3 3s.
L5 5s. L6 6s.
47 =Sympiesometer=, for Ship use L3 3 0 4 10 0
Ditto ditto Pocket form, Fig. 32 4 4 0
The Sympiesometer is now rarely used, the Aneroid Barometer being
found equally sensitive and less liable to derangement.
56 =Independent Standard Thermometers=, Fig. 36 5 5 0
57 =Standard Thermometers=, for Boiling Point Apparatus 1 10 0
=Chemists' or Brewers' Standard Reference Thermometers=
L1 1s. 2 2 0
47 =Chemical Thermometers=, divided on the stem. Fig. 48.
10s. 6d. 0 15 0
=Chemical Thermometers=, Boxwood Scale 7s. 6d. 10s. 6d. 0 12 6
64 =Thermometers on Boxwood Scales=, Fig. 37.
1s. 1s. 6d. 2s. 6d. 3s. 6d. 0 4 6
Ditto ditto larger sizes 7s. 6d. 0 12 6
Ditto ditto Engraved glass scales, Fig. 39
15s. L1 1s. L1 5s. 1 10 0
=POCKET THERMOMETERS, IN VARIOUS MOUNTINGS.=
Fig. 38 10s. 6d. Fig. 40 10s. 6d. 15s.
Fig. 41 5s. 6d. 8s. 6d. 12s. 6d.
63 =Thermometers of extreme Sensitiveness=, 15s. L1 10s. 2 2 0
=Drawing Room or Mantel Thermometers=, various mountings,
Figs. 42 and 43. 12s. 6d. 15s. L1 1s. L1 10s. L2 2s. 2 10 0
=Bracket Window Thermometers=, Fig. 46
12s. 6d. 15s. L1 1s. 1 10 0
=Bath Thermometers=, Figs. 44 7s. 6d. 0 15 0
66 =Sugar Boiling Thermometers= L1 12s. L2 2s. 3 3 0
67 =Earth Thermometers=, Fig. 51 L1 10s. 2 2 0
Hot Bed Ditto 12s. 6d. L1 5s. 1 10 0
68 =Marine Thermometer=, Fig. 52 7s. 6d. 8s. 6d. 0 10 6
65 =Super Heated or Steam Pressure Thermometers=, Fig. 74,
Figs. 49 and 50 L1 5s. L1 10s. L2 2s. 2 10 0
=SELF-REGISTERING THERMOMETERS FOR HEAT.=
72 =Negretti and Zambra's Patent Standard Maximum
Self-Registering Thermometer=,[21] Fig. 54 1 1 0
72 =Negretti and Zambra's Patent Maximum Thermometer=, on
boxwood scale 0 10 6
Ditto, ditto, on Negretti and Zambra's Patent Solid
Porcelain or Metal Scales on oak mounting 0 12 6
70 =Rutherford's Maximum Thermometer=, on boxwood or metal
scale, with steel index 5s. 6d. 7s. 6d. 0 10 6
71 =Phillip's Maximum Thermometer=, on boxwood or metal
scale, with air index 7s. 6d. 10 6 0 12 6
=SELF-REGISTERING THERMOMETERS FOR COLD.=
73 =Negretti and Zambra's Standard Minimum Self-Registering
Thermometer=, Fig. 55 1 1 0
73 =Rutherford's Minimum Thermometer=, on boxwood or metal scale
3s. 6d. 5s. 6d. 7s. 6d. 0 10 6
73 =Rutherford's Minimum Thermometer=, on Negretti and Zambra's
Patent solid porcelain scale 10s. 6d. 0 12 6
Ditto, on Negretti and Zambra's porcelain or metal scales
and oak mounting 0 12 6
74 =Negretti and Zambra's Horticultural Self-Registering
Thermometer.= The scale is made of stout zinc, enclosing
the tube; the figures and divisions are boldly marked for
quickly and easily reading the indications, Fig. 56 0 3 6
83 =Negretti and Zambra's Patent Solar Radiation Thermometer=,
Fig. 63 1 5 0
84 Ditto, ditto, ditto, in vacuo, Fig. 64 1 10 0
Ditto, ditto, ditto, improved form, with test gauge 2 2 0
85 =Negretti and Zambra's Terrestrial Radiation Thermometer= 1 5 0
Brass Stands for above, Fig. 65 0 5 0
76 and 77 =Negretti and Zambra's Patent Mercurial Minimum
Thermometers= L2 10s. 2 2 0
81 =Maxima and Minima Thermometers=, on Sixe's arrangement,
Fig. 62, various forms of mounting
12s. 6d. 14s. 21s. 30s. 2 2 0
=Pocket Maxima and Minima Thermometers=, Negretti and Zambra's
Patent, in convenient cases L2 2s. 2 10 0
89 =Deep Sea Registering Thermometer=, with Negretti and
Zambra's improved protected bulb, in copper cylinder,
Fig. 69. 2 10 0
89[21] =Negretti and Zambra's Improved Deep Sea Thermometer=,
with vulcanite mountings, in copper cylinder, with door,
small size 2 5 0
90 =Negretti and Zambra's Patent Recording Deep Sea
Thermometer= 10 10 0
91 Ditto, ditto, ditto =Recording Thermometer= 4 4 0
92 Ditto, ditto, ditto =Hygrometer= 6 6 0
93 =Improved Boiling Point Mountain Thermometer=, or
Hypsometric Apparatus, with Tables, Figs. 72 and 73, in
leather case with strap 5 5 0
Extra Thermometer for Ditto 1 10 0
106 =Negretti and Zambra's Standard Wet and Dry Bulb
Hygrometer=, Fig. 79 2 2 0
Wet and Dry Bulb Hygrometers, various mountings
30s. 25s. 21s. 14s. 0 10 6
Pocket Hygrometers, in box L2 2s. 2 10 0
103 =Daniell's Hygrometer=, Fig. 77 3 3 0
104 =Regnault's Hygrometer=, Fig. 78 L3 10s. 5 5 0
Aspirator for Ditto L1 15s. 2 15 0
110 =Howard's Rain Gauge=, has a 5-inch copper Funnel, with
turned brass rim fitted to a stout stone-ware or glass
bottle, with a graduated glass measure, divided to 100ths
of an inch 0 10 6
=Symons' Portable Rain Gauge=, (5-inch) with graduated
glass measure, japanned tin 0 10 6
Ditto ditto in stout copper 0 15 0
111 =Glaisher's Rain Gauge=, the receiving surface is 8-inches
diameter, of stout japanned metal, with graduated glass
measure, Fig. 84 1 1 0
Ditto ditto, of stout copper 1 10 0
Receiving Pots for ditto, extra 2s. and 3s. 6d.
113 =Rain Gauge=, having a receiving surface of 12 inches
diameter, and graduated glass gauge tube, divided to
hundredths of an inch, in japanned metal, with brass tap 2 10 0
Ditto ditto, Fig. 85, in copper 3 10 0
Ditto ditto, with sliding rod instead of graduated tube,
japanned tin 2 2 0
=Rain Gauges=, of any form or area made to order, with suitable
measuring glasses.
123 =Lind's Anemometer=, Fig. 86 2 2 0
125 =Robinson's Anemometer=, Fig. 87 3 3 0
Ditto ditto, Improved arrangement L4 10s. 5 15 0
Ditto ditto, with clutch movement, Fig. 88 6 15 0
=Negretti and Zambra's Improved Air Meter=, of extreme
sensitiveness, very portable 4 4 0
Large Air Meters made to order.
127 =Osler's Self-Registering Anemometer and Rain Gauge=,
Fig. 89 L84 to 150 0 0
128 =Berkley's Anemometers= fitted up to order, _to suit the
Observatory_.
131 =Gold Leaf Electrometer=, Fig. 90 1 1 0
133 =Peltier's Electrometer= 4 4 0
134 =Bohnenberger's Electroscope=, Fig. 91 8 8 0
135 =Thompson's Electrometer=, to order
=Lightning Conductors= fitted up to order.
142 =Ozone Cage=, Fig. 92 0 18 0
Ditto ditto, copper 1 5 0
146 =Leslie's Differential Thermometer=, Fig. 93 L1 10s. 2 2 0
148 =Thermometer Stand (Glaisher's)= 3 3 0
149 =Thermometer Screen= for Sea use 3 3 0
150 =Anemoscope=, or Portable Vane, Fig. 94 2 5 0
151 =Evaporating Dish=, Fig. 95 1 2 6
157 =Sea Water Hydrometers=, Board of Trade Marine, Figs. 96
and 97 0 5 6
158 =Newman's Self-Registering Tide Gauge=, Fig. 158, fitted
to the Building to order From 50 0 0
_Further Information as to Price, &c., will be found in_
NEGRETTI & ZAMBRA'S ENCYCLOPAEDIC CATALOGUE OF
MATHEMATICAL, PHILOSOPHICAL, OPTICAL, PHOTOGRAPHIC,
AND STANDARD METEOROLOGICAL INSTRUMENTS,
_Containing very numerous Comparative Tables of Reference,
and Illustrated by upwards of_
ELEVEN HUNDRED ENGRAVINGS.
Royal 8vo. Cloth, Gilt Lettered--Price 5s. 6d.
FOOTNOTES:
[1] Second Number of "Meteorological Papers," issued by the Board of
Trade.
[2] With reference to these barometers, we have received the subjoined
testimonial, with permission to use it as we please.
"_Meteorologic Office, 12th June, 1863._
"MESSRS. NEGRETTI & ZAMBRA,
"The barometers which you have lately supplied to Her Majesty's ships
through this Office are much approved, being good for general service,
afloat or on land.
"(Signed) R. FITZROY."
[3] _Vide_ C. Daubeny, F.R.S., "On Climate."
[4] _Vide_ Report of the British Association, 1862.
[5] See page 42 for the Tables.
[6] The quotations in this section are from Tyndall's _Heat considered as
a Mode of Motion_.
[7] Dr. Daubeny, F.R.S., _On Climate_.
[8] Leslie _On the Relations of Air, Heat, and Moisture_.
[9] Tyndall's _Heat considered as a Mode of Motion_.
[10] Vide _Horological Journal_, Vol. V.
[11] _Hygrometrical Tables_, by J. Glaisher, Esq., F.R.S.
[12] Vide _Report of the British Association_, 1862. It may be added, for
the information of those who are about to commence observing, that Mr.
Symons, of Camden Road Villas, London, is desirous of securing returns of
rain-fall from as many stations as possible, in order to render more
complete his annual reports to the British Association.
[13] Luke Howard's _Climate of London_.
[14] Vide _Third Number of Meteorological Papers_, issued by the Board of
Trade.
[15] _Elements of Physics_, by C. F. Peschel.
[16] This description is modified from that in Report of the Jurors for
Class XIII. International Exhibition, 1862.
[17] _All the Year Round_, No. 224.
[18] _All the Year Round_, No. 224.
[19] Vide _Jurors' Reports_.
[20] See also page 90 of this Treatise.
[21] These Instruments are the only Maximum Thermometers that can be
recommended, as unless they be broken, they cannot be put out of
adjustment. Fully described under the head of Standard Maximum
Thermometers in our large Catalogue, and page 72 of our _Treatise on
Meteorological Instruments_.