moval of which blocks at the end of the operation will afford access for the removal of the ice.

The

ice may be detached from the cone without violence by raising the valve f, and thus allowing hot vapour to come over from the vessel D. But for the manufacture of ice, a vessel of either of the shapes shown in Figures 2 or 3 is preferred; A,

Fig. 2, is a cylindrical vessel of tinned copper, with a depression at the top, narrowing downwards in the shape of an inverted cone, on the outside of which the liquid ether circulates round, along the spiral h; the water to be frozen is contained in the hollow w, which may be fitted with a central block of wood to diminish the quantity to be operated upon, and to this block a revolving motion may be communicated, so as to keep the water in motion until cooled down to the freezing point. The cistern B contains water for the supply of the hollow w; this water will undergo a preliminary cooling from the evaporation of the ether, which reaches the bottom of the vessel A.

In Figs. 3 and 4, Fig. 3 represents the upper surface, and Fig. 4 a vertical section of another form of freezing vessel. Here A is a vessel of tinned copper, with long wedge-shaped depressions w, to be filled with the water to be frozen; the freezing goes on from both surfaces of the depression. The wedges of ice thus formed may be placed together SO as to form large blocks. The ice may be detached, as already described, by the admission of hot vapour, or the water may be frozen in tinned copper moulds, accurately fitting the depressions, and these may be removed, and the ice turned out at a temperature lower than would otherwise be attainable.

Where the object is to lower the temperature of apartments, larders, wine cellars, &c., the evaporating vessel is uncovered, and a separate room

appropriated for the pump and condenser. With this arrangement of apparatus, the double operations of refrigerating and heating, may be carried on in different apartments simultaneously.

If it is desired to form an extensive surface of ice, the evaporating vessel may be replaced by a coil of pipe, during its passage through which the liquid ether may be evaporated.

The apparatus just described was patented in 1856. In 1857 a second patent was taken out for improvements in the refrigerating apparatus. In the new form the cold produced by the evaporation of the ether is made to act on a stream of saline or alkaline solution (the freezing point of which is much lower than that of water), and the brine thus cooled is made to pass over the outer surfaces of the vessels or moulds containing the pure water intended to be frozen. In this way ice can be produced in large square slabs, which being taken out and piled one on another, form a solid of considerable dimensions.

In the International Exhibition of 1862, Harrison's ice-making machine attracts crowds of visitors. The exhibitor draws out of the machine large solid plates of ice, which with a pointed tool he splits into numerous fragments, and distributes among the spectators. Thus in the sunny June days, the visitors to the eastern annex were seen walking about in the heated building with pieces of ice in their hands, which were often applied to the lips as a welcome source of refreshment.

R

CHAPTER VI.

AMUSEMENTS ON THE ICE.

THE winters of England, when most severe, are generally the most agreeable to young and healthy persons, who are able to take plenty of exercise in the open air. Without any dread of being frost-bitten, they hasten forth as soon as the cold is established to enjoy their favourite amusements on the ice. Nor must we suppose that the winters of colder climates are without their beauty and enjoyment. The effect of wind in increasing the power of cold over the human frame, is well known even in this country, and is felt distressingly in northern regions; but in still, bright weather, the cold, though intense, is bearable and even pleasant. Thus an English lady, writing from the frozen shores of the Baltic, where she passed a winter, says: "There is something very exhilarating in this breathless, still, bright, cold, with a clear white expanse, a spotless world before you, every tree fringed, every stream stopped-freedom to range over every summer impediment; while the crystal snow lighting up into a delicate pink or pearly hue, or glistening with the brightest prismatic colours beneath the clear low sun, and assuming a beautiful lilac or blue where our long shadows intercept its rays, can no longer be stigmatised as a dead, lifeless white."