132 The Horticulturist' s Rule-Book. 



6. Per Cent, of Rays of Lignt Reflected from Glass Roofs at 

 Various Angles of Divergence from the Perpendicular. 



(Bouguer. ) 



1° 2.5 per cent. 



10° 2.5 



20° 2.5 



30° 2.7 



40° 3.4 



50° 0.7 



60° . 11.3 



70° 32.2 



80° 41.2 



85° 54.3 



7. Area of Glass in Various States and Provinces, used for 



Commercial Greenhouse Purposes. 



(Stewai-t.) 



Glass in use , INCREASE IN 1887 ^ 



previous For ciit- For Total 



to i8Sj. flowers. plants. increase. 



Alabama 50,000 3,000 6,780 9,780 



Arkansas . . .' 14,474 8,188 4,150 12,338 



California 213,660 59,810 32,200 92,010 



Connecticut 35,071 17,551 52,622 



Delaware 79,100 . . . 3,000 3,000 



District of Columbia . . 125,000 37,100 4,000 41,000 



Florida 20,000 20,000 10,000 30,000 



Georgia 33,100 2,400 500 2,900 



Illinois 1,422,533 12,676 36,824 99,500 



Indiana 142,866 20,575 23,240 43,815 



Iowa 125,580 27,900 13,110 41,010 



Kansas 31,600 1,800 2,250 4,060 



Kentucky 320,400 



Louisiana 24,420 11,400 ' 7,600 19,000 



Maine 102,033 19,130 4,000 23,130 



Maryland 185,526 29,908 .... 29.908 



Massacbusetls 1,375,000 53,000 ... 53,000 



Minnesota 138,500 22,600 • 5,600 28,200 



New Hampshire 86,450 11,825 3,275 15,100 



New Jersey 2,114,245 297,529 59,504 357,033 



