214 



Apparatus, Supplies and Materials for General Use. 



NO. 



51287. 1:4. 



51293. 1 : 5. 



51288. 1 = 7. 



51294. 1:3. 



51297. 1:3. 



51301. 1:5. 



51,286. American Freezer, Figure, for making pure ice or preserving ice by a cold mixture; s- d - 

 freezes 1V 2 1 water in 15 minutes, or ice-cream in 8 to 12 minutes. Convenient 



to handle. With description and recipes 0. 12. o 



The refrigerating medium in these machines is a mixture of ice or snow with salt. 



."1,287. Ice Chopper for above, Figure 0. 1. 6 



51,288. Ice Machine (Liebreich's), Figure, for making small quantities of absolutely pure 



ice; produces 500 600 g ice in 15 minutes 1. 16. 



The action of this machine is based on the fact that ammonium nitrate takes up heat on going 

 into solution so that the temperature falls about 25 C. The ammonium nitrate necessary for making 

 the ice is recovered by evaporation of the solution, and the ice is therefore very conveniently and 

 cheaply produced. Ice and salt are not used for freezing in this machine. 



."l.L'89. --The preceding, for making from 1000 to 1200 g in 15 minutes .... 3. o. o 



51,290. Enamelled kettle for the volatilisation of the ammonium nitrate 0. !. o 



."I. _'!!. Vessel for preserving the ice blocks 0. 11. > 



51,292. Mercury, chemically pure and dry Per kg 0. s. u 



">l.i'!t:5. Mercury Board, Figure, can be used as a tray, 60x40 cm 0. 7. 



The mercury tray is intended for taking the apparatus involving the use of mercury so that 

 any mercury which may be spilled is collected on the board. The board is of oak, and has a raised 

 edge 30 mm in height and, in one of the corners, an escape hole. 



ci. l HI. is:.. 



1. V.. 1SI1. 



