APPENDIX. 343 



2d, room cooled 13 in 125' = 1 in 9-6', windows closed. 

 3d, room cooled 10 in 88' = 1 in 8-8', windows closed. 

 " " 10 in 50 7 = 1 in 5-0', windows open. 



Experiment with wooden shutters : 

 Room cooled 10 in 93' = 1 in 9-3', shutters closed. 

 " " 10 in 58' = 1 in 5-8', shutters open. 



From the above, the effect of glass is very evident, and also the advan- 

 tage of curtains and shutters. We shall not attempt to form any gen- 

 eral rule, since it could be applied correctly only under circumstances 

 which differed very little from the above. 



The preparation for covering white cotton for interior windows is 

 composed of 4 oz. of pulverized dry white cheese, 2 oz. of white slack 

 lime, and 4 oz. of boiled linseed oil. These three ingredients having 

 been mixed with each other, 4 oz. of the white of eggs, and as much of 

 the yolk, are added, and the mixture then made liquid by heating. 

 The oil combines easily with the other ingredients, and the varnish re- 

 mains pliable and quite transparent. It is applied with a brush. 



