There are two methods of arranging the chains--called the over-shot and the under-shot. The first named is mostly used, and is the one shown in Plate _C_. The power required varies with the length of the incline and with the style of the elevators, which are arranged for one or two cakes on a bar. The smaller rigs are operated with an eight or ten horse power engine, and the larger plants up to one hundred horse power, where several elevators and platform conveyors are coupled on to one engine. For filling smaller houses there are several methods in use, a choice depending on the surroundings and size of the room or house. Next in importance to the endless chain system, are the jack grapples by which large quantities of ice are annually stored. An incline is used which is similar to the one shown on Plate _C_, but of lighter build. These grapples are operated with horses, or with steam power, when winding drums are employed. By using friction-winding drums, the jack grapples readily accomplish the work of a single elevator, and are less expensive. This plan is shown in Plate _E_. An ordinary threshing engine furnishes ample power, and this method is rapidly growing in favor. Where the ice house is placed at the edge of the water and there is no room in which to place an incline, the gigs are very convenient. When they are operated by means of a winding drum run by a reversing engine, and large enough to handle four cakes at a time, they are very efficient. Economy of power, simplicity and ease of management, are all in their favor. Small houses and cooling rooms are filled with the aid of hoisting tongs. CHAPTER V. CARE, HANDLING AND MARKETING OF ICE. Care of Ice in the House--Leaking and Waste, How Prevented--Getting out Ice--Lowering Machines--Ice Shipments--Marketing Ice--Ice Wagons and Outfits. After a house is filled with ice and put in order, it is placed in the care of an attendant. The top dressing requires frequent inspection to keep it intact. Keep the circulating air-chambers in the walls in operation, except when the air is humid; at such times the lower openings are closed. The loft is ventilated directly into the cupola on top of the roof, which also carries off the warm air currents rising through walls. THE WASTING OF ICE.--Ice in the house is attacked by water, moisture, vapor, warm air and evaporation. Pressure of the mass upon the lower courses assists in their destruction, and heat from the earth is also radiated into them. Evaporation goes on, to some extent, at all temperatures; its immediate effect is cooling, as it carries off heat. Water rots and wastes ice more rapidly than warm air. Water permeates the mass and destroys the ice, while warm air affects only the exposed surface. Vapor is wasteful when it settles down on the ice and is condensed. Air currents, if they are strong, cut away the ice very rapidly, and will sometimes comb the ice.