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Striking differences between natural and artificial objects, 47.-

Numerous properties of ice, 48.-Its formation, 48.—Distri-

bution of heat, by radiation, conduction, and convection, 48.

- Expansion and contraction, 49. — Maximum density of

water by cold, 49.—The freezing point, 50.—Expansion by

cold, 50.- Experimental illustrations, 50.—The process of

convection illustrated by the freezing of a lake, 52.-Lowering

of the freezing-point in still water, 52.—Heat of liquefaction,

53.-Why deep lakes freeze slowly or not at all, 53.-Freezing

of rivers-ground-ice, 53.---Freezing-point of salt water, 53.-

Expansion of water by cold—experimental illustrations, 54.

-Freezing, at the surface and at the bottom, 55.—Ultimate

effect of freezing at the surface, 56.- Maximum density of sea

water, 56.—Mechanical force of water in freezing, 58.--Dis-

integration of soils, rocks, and building stones, 59.-Brard's

method of detecting porous stones, 60.-Further illustrations

of the mechanical action of frost, 60.-Freezing of fish ponds,

61.—Making holes in the ice, 62.-Avidity for air varies in

different fishes, 62.—Supply of air to an aquarium, 63, note.-

Ventilation of frozen fish ponds, 1, by feeders, 2, by springs,

64.—3, by absorption of the soil and infiltration, 65.—Forma-

tion of cats' ice, 65.- Temperature of the water beneath the

ice, 66.--Frost smoke, 66.-Penetration of the soil by frost,

66.-Purity of ice, 68.—Water in freezing excludes foreign

matter, 68.—Burning lens of ice, 69.—Expansion and contrac-

tion of ice by variations in temperature, 70.-Colour of ice,

70.-Conduction of sound by ice, 70.-Specific gravity of ice,

71.--Latest determination of, 72.—Welding of pieces of ice

above 32° Fahr., 72.-Regelation, 74.-Experimental illustra-

tions, 75.-Ice of different fusibilities, 79.—Dr. Faraday's ex-

planation of, 79.—Dr. Tyndall's experiments on regelation, 81.
- Moulding of ice, 81.-Crystalline form of ice, 83.—Ice

snow and ice, 185.—Ice-cellars, glacières or ice-houses, 186.-

Drinking-cups of ice, 186.-Iced fruits, liquori, and lemonade,

187. Limonadiers, '188.—Natural ice-caverns, 188. — Ice

cavern in South Russia, 189.- Accounted for on the principle

of evaporation, 190.-Ice caverns in Hungary, 191.—Beautiful

appearance of the ice, 192.-Ice mountain in Virginia, 193.-

Ice bed in Vermont, 194.–Natural ice house in Connecticut,

194.–Natural ice house near Newhaven, 196.-Snow-hole in

Massachusetts, 197.-Frozen well near Owego, 197.-Artificial

production of ice by evaporation, 198.- Applied to explain

the existence of these ice-caverns, 198.—Principle on which

an artifical ice-house is constructed, 199.-Ice heap, 200.--

Best site for an ice-house, 201.-External form and depth of

the well, 202.-Drainage, 202.—Sides of the well, 203.-

Covering of the ice-house, 203.—Entrance doors, 204.–Filling

in the ice, 205.-Air-trap, 205.—Bottom of the well, 205.-

Details of the construction, 207.-Ramming in the ice, 207.-

Various forms of ice-house, 208.-Improved ice-house, 209.-

Square ice-house, 210. — Use of watering the ice, 210.-

Portable ice-house, 211.—The refrigerator, 212.-Keeping

provisions in ice, 212.–Storing of ice in Russia, 213.-Frozen

markets of Russia, 214.



The ice-harvests of America, 217.—Commencement of the trade,

217.-The markets for Boston ice, 218.-Yield of the American

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