Latent heat, first taught by Dr.
Black, 84; what it is, 278, 336;
of steam, 283, 337.
Lavoisier's measurement of dilata-
tion, 26.

Laws, of dilatation of solids, 24;
of dilatation of crystals (Mitscher-
lich), 37; of dilatation of liquids,
52; Boyle's law, 53; of expansion
of gases (Gay Lussac's law), 55; of
dilatation of gases (Regnault), 61;
of fusion, 82; of solidification, 87;
of maximum pressure in vacuo
(Dalton), 96; of mixtures of gas
and vapours, 96; of evaporation,
107; of Leidenfrost's phenome-
non, 114; of relation between
volume and temperature of gases,
121; of density of gases, 133; of
relation between temperature and
refraction (Gladstone and Dale),
148; of electric currents (Seebeck),
148; of radiation of heat, 159;
of reflection of dark heat, 173;
of refraction, 175; of polariza-
tion, &c., 179; of radiation (ex-
changes), 190; of internal ra-
diation, 198; of absorption and
radiation, 204; of velocity of
cooling, 209; of radiation from
black bodies, 214; from gases,
217; of dew, 231; of fluorescence,
235; of flow of heat across a wall,
243; of conduction of crystals,
255; of cooling due to a gas, 260;
of specific heat of solids, 267,
268; of liquids, 270; of gases
(Regnault), 274; of atomic heat,
277; of energy, 298; of thermo-
dynamics, 301.
Leidenfrost's phenomenon, 113.
Length, standard of, 65-67.
Leslie's differential thermometer, 22;
first to freeze water by evapora-
tion, 101; experiments on reflec-
tion of dark heat, 170; table of
results, 171; on radiation and re-
flection, 185; on oblique radiation,
188; on law of cooling in gases,
261.

Light, its heat reflected, 172; and

heat, probably identical, 179;
heat, and sound, analogy of, 204;
absorption of, 226; energy of,
298.

Light rays, equilibrium of, 198.
Linear dilatation of uncrystallized
solids, 26-36.

Liquefaction and solidification, 80-
93; latent heat of, 279.
Liquids, dilatation of, 39-52; elec-
tric conductivity of, 155; con-
vection in, 256; specific heat of,
2.69.
Locomotives, 330.

Machines, functions of, 294.
Magnetism, effect of temperature on,
155; disturbances of, due to the
sun, 358.
Magneto-electricity, experiments by
Foucault, 304.

Magnus on dilatation of crystals, 38;
of gases, 55; on mixed liquids in
a confined space, 97; on boiling-
points of saline solutions, 110; on
the effect of air dissolved on
boiling-point, III.

Malus on polarization, 177.
Marcet's experiments on boiling-
point, IIO.

Marchand on Leidenfrost's pheno-
menon, 114.

Marianini on electric conductivity,
155.

Marriotte's law of dilatation of gases,

Measures of time, how affected by

temperature, 73.
Mechanical energy convertible into
heat, 294.

Melloni's proof of law of radiation of

heat, 164; uses pile and rock salt,
173; on refraction of dark heat,
173; on radiation of air, 217;
table of absorption of heat, 222.
Melting-points, 82; table of, 83;
change of density at, 83; effect of
pressure on, 84.

Mercurial pendulum (Graham's), 74.
Mercurial thermometer, process of
filling, 7; calibration of, 8; de-
termination of freezing-point of,
9; determination of boiling-point
of, 10; graduation of, 13; various
scales of, 13; correction for change
of zero of, 15; other sources of
error of, 16; with crown glass en-
velope, errors of, 64.
Mercury, dilatation of, 41; specific gra-

vity of, 71; freezing-point of, 83.
Metal, Rose's fusible, 37.
Metallic precipitates, 343.
Metallic thermometer (Breguet's),
77; reflection, 227.

Metals, expansion and contraction of,
78; in thermo-electric series, 149;
electric conductivity of, 154; light
rays from polished, 199; relative
thermal conductivity of, 249.
Mètre, French standard, 67.
Miller, restored standard pound, 69.
Miller's (W. A.) table of boiling-
points, &c., 112; on spectra of
heavenly bodies, 221.
Minimum thermometer, 21,
Mitscherlich's observations on dilata-
tion of crystals, 37.
Mixture method of measuring specific
heat, 264.
Mixtures, freezing, 85,

Molecular energy, 297; converted
into heat, and vice versa, 336;
state, gradual change of, 338.
Mont Blanc, boiling-point on sum-
mit of, 109.

Motion, radiation is probably undu-
latory, 161; perpetual, 287.

Mousson's experiments on ice, 85.
Musical sounds, analogous to radiant
heat, 162.

Natterer's mixture for evaporation,
102; on condensation, 120.
Nebula, composed of incandescent
gas, 221.

Negretti and Zambra's maximum
thermometer, 20.

Neumann on atomic heat of com-
pounds, 277.

Newcomen's steam engine, 325.
Newton discovered composition of
light, 166; his law on cooling, 207;
recognised the functions of a ma-
chine, 293.

Nobili's thermo-pile, 173.

Optics, phenomena of, reproduced in
radiant heat, 165; also in dark
heat, 179.

Oxygen, combustion in, 342.

Papin's digester, 109; his steam
engine, 324.

Particle, radiation of a, 216.
Peclet on conductivity, 243, 250.
Peltier, 336.

Pendulum, Graham's mecurial, 74;
Harrison's gridiron, 74; energy
of, 293.
Perfect engines, 318.

Perpetual motion, 287; why im-
possible, 348.

Person's experiments on latent heat,
281.

Petit and Dulong's observations on
cubical dilatations, 34; method
of measuring dilatation of liquids,
42; of gases, 55; experiments on
cooling in vacuo, 207; in a gas,
260; on specific heat, 267; on
atomic heat of bodies, 276.
Phillips' maximum thermometer, 20.
Phipson on dilatation of crystals,
38.
Phosphorescence, 232; likeness to
fluorescence, 236; practical uses
of, 237.
Phosphoroscope, 233.

Photography, chemical change in,
346.

Pictet's experiment on apparent ra-
diation of cold, 182.

Pierre's researches on dilatation of
watery solutions, 48; of other
liquids, 49; table, 50; laws of
contraction of liquids, 52; ob-
servations on boiling-points, 112.
Plate, white, light rays from, 199.
Plates, bundles of, used for polariza-

tion, 178; thin, heat equilibrium
of, 191; light rays from, 200.
Platinum, specific heat of, 268; use-
ful as pyrometer, 268.

Poggendorf on Leidenfrost's pheno-

menon, 114.

Polarization, 163; of heat, 177,
189.

Polished metal, light radiation from,
199.

Porta's conception of a steam engine,
324.

Potential energy, 292.

Pouillet's measurement of dilatation,
28; specific heat of platinum,
269; instrument for measuring the
sun's heat, 359.

Pound Troy, formerly English stan-
dard of weight, 68.
Precipitates, metallic, 343.
Pressure, of air, 56; effect of, on
melting-points, 84; effect of, on
solution, 86; vapour pressure in
vacuo and in gas, 96, 97, 98, 104;
influence of, on boiling-point, 108;
of vapour, 120; of aqueous vapour,
122; correction for latitude, 129;
remarks on, 132; effect of, in
lowering freezing - point, 362;
tables of, 369.

Prevost's theory of exchanges of
heat, 181.

Prince Rupert's drops, 338.
Provostaye and Desains on reflection,
172; on absorption of heat, 176;
on exchanges, 183; on radiation
and reflection, 186; on polariza-
tion, 190; on cooling, 213; on
latent heat, 280.
Pyrheliometer, 359.

Pyro-electricity, 153.

Pyrometer, Wedgwood's, 24.

Quality of heat, 189, 214; eye sen-

sitive to variety in, of rays, 215.
Quantity of radiation, 189, 207.

Radiant heat, defined, 159; radiation
in vacuo, 160; on all sides, 160;
with same velocity as light, 160;
can pass through some substances,
160; is probably undulatory mo-
tion, 161; laws of its intensity,
164; reflection of, 169; refrac-
tion of, 173; absorption of, 175;
polarization of, 177; theory of
exchanges, 181; equilibrium of,
184; of rock salt, 191; of glass,
191; of thin plates, 192; internal
radiation, 193; from lamp-black,
206; absolute measure of, 213;
of a particle, 216; of gases, 216;
energy of, 298.

Radiators, bad, are good reflectors,
185.

Ramsden's measurement of dilata-
tion, 26.

Rankine on energy, 296, 297.
Rapidity of refrigeration in Central
Asia, &c., 230.

Rays of light, how composed, 166;
their properties, 168; equilibrium
of, 199.

Reaumur's thermometer, 13, 14.
Reduction of Fahrenheit's, Centi-

grade, and Reaumur's scales, 14.
Reflection of heat, 169; apparent,
of cold, 182; metallic, 227.
Reflectors and radiators, 185.
Refraction affected by temperature,
147; of heat, 173.

Refrigeration, rapid, in Central Asia,
230.
Regelation, 89; probable explana-
tion of, 89-92.

Regnault's apparatus for ascertaining
temperature of steam, 11; obser-
vations on dilatation, 34; method
of measuring dilatation of liquids,
42; method of investigation of
dilatation of air, 59; of gases, 60;

laws, 61; air thermometer, 63;
experiments on mixtures of gas
and vapour, 97; on vapour from
mixed liquids, 97; researches on
pressure of aqueous vapour, 123;
of other vapours, 131, 132; on
density of gases, 135; table of
weight of a litre of gases, 137;
hygrometer, 141; experiments on
specific heat, 266, 269, 271; on
latent heat, 281; of steam, 283.
Reich and Richter discovered indium,
219.

Reversible engines, 310.

Rock salt transmits heat freely, 175;
small radiation from, 191.
Rose's fusible metal, 37.
Rubidium, how discovered, 219.
Rudberg on boiling of water, 10;
dilatation of gases, 55; on boiling-
points of saline solutions, III.
Rudorf's experiments on solutions,
93.
Ruhmkorff's machine, 331, 358.
Rumford, Count, on latent heat,
283; on conversion of energy
into heat, 295; on energy of
animals, 355.

Rupert's, Prince, drops, 338.
Rutherford's maximum thermometer,
20; minimum thermometer, 21.

Simple bodies, atomic heat of, 276.
Sodium, metallic, vapour of, 217.
Solar spectrum, 166.

Solid bodies, spectra of heated, 168.
Solidification and liquefaction, 86-

93.

Solids, dilatation of, 24-39; uncrys-

tallized, 24-37; crystallized, 37;
conduction of homogeneous, 240;
of non-homogeneous, and of crys-
tals, 254; specific heat of, 266.
Solution, 85; effect of pressure on,
86.

Sorby on influence of pressure on so-
lution, 86.

Sound and light, analogy between,
204.

Sources of energy, 354.
Southern, 283.

Space pervaded by a material me-
dium, 352.

Specific gravities, table of, 112; of
air and gases, 138, 144.
Specific gravity bottle, 40.
Specific heat, 263-277; of gas of
constant volume, 307.

Spectra of heated bodies, 168; of
gases, 217.
Spectroscope, 217.

Spectrum, what, 166; of light and
heat, 168; chemical, 168; its cha-
racter and use, 179.
Spheroidal state, 113.
Standard of length, 65; of weight,
68; of density, 70; French and
English, 71.

Stars, constitution of, 219.
State, change of, 81-146; spheroidal,
113; influence of state on specific
heat, 275.

Steam, temperature of, denotes 212°
Fahrenheit, 10; pressure at vari-
ous temperatures, 122, 369; latent
heat of, 283; engine, history of,
322; saturated, 337.
Stephenson's locomotive, 330; on
potential energy of food and fuel,
355.

Stewart, Balfour, fluctuation thermo-
meter 23; on pressure and temper-
ature of air, 56; developes theory

of exchanges, 184; experiments on
light, 198; remarks on the aurora,
358.

Stokes' method of observing light

rays, 202; on connection between
absorption and radiation, 204;
correct conjecture as to spectra,
220; on absorption of light, 226;
on reflection from metals, 227;
explanation of fluorescence, 235-
Stream of radiant heat, laws of, 191,
205.

Sublimation, 94, 117.

Sulphur, native, energy of, 357.
Sun and stars, constitution of, 219;
direct rays of, a form of energy,
354; sun is ultimate source of
energy of food and fuel, 355; of
head of water, 356; of air and
water in motion, 357; instrument
for measuring heat of its rays,
359; origin of heat of, 361.
Surfaces, heat equilibrium of, 184;
light equilibrium of, 199.
Svanberg on conductivity of bismuth,
254.

Swan's remarks on sodium, 218.

Tables, of temperature of steam
under pressure, 11; of dilatation
of uncrystallized solids (linear), 30,
(cubical), 34, 35; of dilatation of
mercury, 46; of water, 49; of
other liquids, 50; of dilatation of
volatile liquids, 51; of contraction
of alcohol and sulphuret of car-
bon, 51; of dilatation of gases,
60; of comparative temperatures,
64; of comparison of French and
English standards, 68, 69; of
melting-points, 83; of freezing-
mixtures, 86; of boiling-points and
specific gravities, 112; of vaporiza-
tion (Cagniard de la Tour), 116;
of pressure of vapours, 132; of
densities of gases and vapours,
133; of density of steam, 136;
of gases, 137; of vapours, 138;
of effects of temperature on te-
fraction, 148; of electric conduc-
tivity, 154; of reflecting powers,

171, 172; of velocity of cooling
(Duiong), 208; of radiations in
vacuo, 213; of absorption of
heat (Melloni), 223; of gases,
225; of thermal conductivity of
metals, 249; of variation of the
same with temperature, 251; of
comparison between thermal and
electric conductivity, 251; of rise
of specific heat with temperature,
267; of specific heat of platinum,
268; of specific heat of solids,
269; of water, 270; of gases
under constant pressure, 274; of
influence of state on specific heat,
276; of atomic heat of simple .
bodies, 276; of compound bodies,
278; of latent heat of liquids,
282; of steam, 284; of vapours,
285; of work done by steam
engines, 329; of heat of combus-
tion, 342; of aqueous vapour, 369.
Tait on tidal energy, 356.
Temperature, preliminary definition
of, 5; equilibrium of, 5; instru-
ments for measurement of-ther-
mometers, 7-23; other instru-
ments, 24; measured by air ther-
mometer, 61, 368; effect on stan-
dards of length, mass, and density,
65; effect on measures of time,
73; on barometric column, 77;
effects of, on refraction and dis-
persion, 147; on electrical pro-
perties of bodies, 148-155; on
magnetism, 155; on chemical
affinity, 156; on other properties
of matter, 156; moveable equili-
brium of, 182; affects quantity
of radiation, 207; affects quality
of heat, 214; affects thermal con-
ductivity, 250; affects specific
heat, 267, 270; absolute zero of,
321; energy derived from differ-
ences of, 354; explanation of, 364.
Thallium discovered, 219.
Theory, true test of a, 367.
Thermal conductivity, 240, 243;
similar to electric, 251.
Thermo-dynamics, iaws of, 301-
321.