GREENHOUSE 



passing through such lenses, and it is not diffioult to sc 

 that the same effect maybe produced tiy sitiiil:irly in 

 perceptible variations in the thiclinfss .if sh.i f -las- 

 That this is the case has been conclu^i\.iy -Imwn !■ 

 the series of experiments before meutioiH-a. Tin -^ ;il- 

 show that burns on plants, caused by dtt'ii-tix .■ -hi- 

 roofs, occur in lines and not in isolated spots, hurt] 

 of the latter description being usually the result of 



GREENHOUSE 



691 



I of 1 ght ays by i 



aken ng or 1 ter or 



Greenhouse Heating —I 



11 

 ' the f e 



:ula pane of elass 



lue to ca elessness 

 V of the atmo 

 of Greenhouses 

 f roof 



t n la s of un 



1 f 1 heaper 



1 1 e lower 



I n the 



g n the 



Bla r 

 vh ch the 



po nt t ne 

 sary tpodeo hi nfl 



house Nea Ij II 1 1 



e ther by steam o 1 1111 1 



occas o ally use 1 \\ 1 I 1 I 1 



small ranges of gl 1 1 1 1 1 I t 



f rn sh an even de e of h t hen 1 tt f ml 



of hours team s n ore co ilmonly used for exten e 

 plants a the cost ot p p ng the ho ses u h 1 ss 



than wl en 1 ot w t r u e 1 Steam bo le s requ e 

 no e ttent on fl It tit but ■« hen there 

 s o e tl 10 011 10) ef et of glass t 



1 t t h n I t t It hman an 1 the 



t ] 1 n 1 I 1 tl n n the cos 



of fu 1 t 11 I e 1 II I rade of 



o 1 L 1 these cond t 1 a stean 



pla t 11 I e 



loi 



aall 



! hard coal 

 att nt n for s x to e ght 

 water heaters w 11 be che 

 nost sat sfactory See al 

 As the var ous flowers 

 gla req re 1 ffe ent t 

 LI I t I 



tl I t 1 



ire used, and are so arranged that 

 it off, the danger from this source 

 fd. The use of two or more small 

 • und much more economical than 

 I lie fall or spring, when it will be 

 in a fire in one of the small boilers 



forcing th.- hvi\ as tins will nut only give more satisfac- 

 tory n-n'i -. Ini \- ;il n uli ill the economy of fuel and 

 labor, a 1 :' ' Mr of the boiler. Boiler 



maki-r- -n .: liinite ratio between the 



size 111 iIm _;,.:. I :ii ,>iM.,iiiit of fire surface in the 



boik-r. in; in n. - .. iili ilio size of the boiler and the 

 efficifii' \ iiliiir liri -iiiriLcu. lu small hot water boilers, 

 with M ly . iii.iiM lire surface, the ratio between the 

 two is 1 ii'iiiiriii [y as small as 1 to 15, while in larger 

 boilers it is nth ii as great as 1 to 35, and even more 

 where hard coal is used and the boilers have constant 

 attendance. For small Greenhouses it is desirable to 

 have the grate sufiiciently large to permit of leaving the 

 fire without attention for eight to ten hours in the se- 

 verest weather, while for a large range of houses it is 

 custo a to e pi \ n ht fi e n n and a (,rate nuch 



mailer \ 

 the cap 

 of r d 

 about I 

 lent t 

 that 1 



m 11 

 of med 



d t 



I lers 

 f t 



fire surface 

 I feet of rad 

 as 1 ot water 



1 1 r of the 

 000 lu e 

 al o e figure 

 Ian e dur ng 

 an allowance 



1 o ler s re 

 e th t ould 



have them 1 1 the 



ent re h 11 hllelw tl the e 



bo lers w 11 1 e 1 eii 1 an 1 

 f p operly are 1 f r w 11 1 u a 1 1 11 



Dur ng tl e p t few y a a lar e u nbe of o 1 

 1 o lers 1 e been con tr t 1 f r hot w te heat ng 



These bo ler a e gen rally fron 4 to 6 feet long and are 



r 1 h a 1 nat 1 

 00 cu umbers an 1 I 



Bo I s —Whether 

 heat n" th 1 t b I 

 feet of ra 1 

 esp 11 



n 1 ed When o ly one 1 o ler u 1 t n ght 



e ult in the loss of all the plants m the house if any 

 accident should happen to it in severe weather, while if 



mak ng the 1 o ler the p pe a e t of he des red 

 length, usuall> of 5 or 6 feet, and the ends are con 

 nected either by return bends or by manifolds, so as to 



