342 



APPENDIX, 



TABLE IX. 



Experiments on the Cooling Effect of Windows.* 



These experiments were made in a wooden house, double plastered, 

 with a space between the two plasterings ; walls 6 inches thick. Heat 

 introduced from a hot-air furnace, heated air being shut off when the 

 room was heated to a proper temperatui'e. Thermometer four feet from 

 the floor. When the windows were closed, two thicknesses of blankets 

 were fastened closely to the window-frame internally. 



Three windows, equal to 33-21 square feet ; walls, 531 square feet ; 

 cubic contents of room, 1930 feet, being 9 feet high, 165 feet long, 13 

 feet wide. 



The room was kept as nearly as possible under the same circum- 

 stances. 



External Internal Tinip 



Thermom. Thernioni. 



o o h. m. 



74 ^ ^ i Weather calm, windows 



64 10 15 / uncovered. 



March 19, i843. 26 

 25 



March 20. 



March 21. 



50 



The experiments were also made in other rooms, with wooden shut- 

 ters internally. 



The results are as follows : — 



1st, room cooled 10^ in 74' = P in 7-4', windows open. 

 " '' 15' in 144' = P in 9-6', windows closed. 



2d, room cooled 10 in 76' = 1" in 76', Avindows open. 



* \Vvni^;i on Ventiialior*. 



