ICE-SPAR 



879 



1205 



nary depth for a family may be about 24 feet; but the larger its dimensions are, the 

 longer will it preserve the ice, provided it be filled. In digging, the workman 

 should slope the ground progressively towards the axis of the cone, to prevent the 

 earth falling in. This conical slope should be faced with brick or stone work about 

 one foot thick, and jointed with Koman cement, so as to be air- and water-tight. A 

 well is to be excavated, at the bottom 2 feet wide and 4 deep, covered at top with an 

 iron grating for supporting the ice, and letting the water drain away. 



The upper cone may likewise be built of brick- work, and covered with thatch ; such 

 a roof would prove the most durable. This is the construction shown in Jig. 1205. 

 Whatever kind of roof be preferred, there must be left in it an oblong passage into 

 the interior. This porch should face the north, and be at least 8 feet long by 2 feet 

 wide; and perfectly closed by a well-fitted door at each end. All round the bottom 

 of this conical cover, a gutter should be placed to carry off the rain to a distance 

 from the ice-house, and prevent the circumjacent ground from getting soaked with 

 moisture. 



Fig. 1205 shows the section of a well-constructed ice-house, Under the ice-chamber 

 A the ice is rammed into the space u. c is the grate of the drain-sink D. The portion 

 E E is built in brick or stone ; the base L of the 

 ice-chamber slopes inwards towards the centre 

 at c. The upper part of the brick-work E E is a 

 little way below the , level of the ground. The 

 wooden framework, F F F F, forms the roof, and is 

 covered with thick thatch. GH is the wooden 

 work of the door i. At K the bucket is seen 

 for lifting up a charge of ice, by means of the 

 cord j passing over the pulley M, which enables 

 the servant to raise it easily. 



The ice-house should have no window to admit 

 light, but be, so to speak, hermetically sealed in 

 every point, except at its cesspool, which may 

 terminate in a water-trap to prevent circulation 

 of air. 



A clear day should be selected for charging the 

 ice-house ; but before beginning to fill, a quantity 

 of long dry straw should be laid on the bottom 

 crosswise; and as the ice is progressively intro- 

 duced, straw is to be spread against the conical 

 sides, to prevent the ice from coming into contact 

 with the brick or stone-work. The more firmly 

 compacted the ice is, the better does it keep ; with 

 which view it should be broken into pieces with 

 mallets before being thrown in. No layers of 

 straw should be stratified among the ice, for they would make its body porous. Some 

 persons recommend to pour in a little water with the successive layers of ice, in order 

 to fill up its small crevices and convert the whole into one mass. 



Over the top layer a thick bed of straw should be spread, which is to be covered 

 with boards surmounted with heavy stones, to close up the interstices in the straw. 

 The inner and outer doors should never be opened at once ; but the one should always 

 be shut before the other is opened. 



Dry snow well rammed keeps equally well with hard ice, if care be taken to leave 

 no cavities in the mass, and to secure its compactness by sprinkling a little water 

 upon the successive charges. 



To facilitate the extraction of the ice, a ladder is set up against its sloping wall at 

 one side of the door, and left there during the season. 



Ice imported in 1871 : 



Tons Tons & 



From Norway . . 95,448 82,865 139,321 128,196 



Other countries . 508 398 100 55 



95..956 83,263 139,421 128,251 



ICE-MANUFACTURE. Siebe's, Harrison's, and Carre's machines for making 



ice are described at page 488. See FREEZING. 



ICE-PIiANT. The Mesembryanthemum crystallinum is so called in allusion to 



the appearance of the surface of the leaves, which are studded with small watery 



vesicles. The ashes of the plant yield soda. 



ICE-SPAR. A transparent glassy felspar, referred partly to sanidine and partly 



to anorthite. 





