384 STATE HORTICULTURAL SOCIETY. 



point upon clay soils. On the whole, we are much pleased with the vetch 

 as an orchard plant, and shall use it again. 



Samples of this vetch including four to six inches of the roots, gave the 

 following fertilizer analysis: 



Original substance. Dry sabstance. 



Nitrogen .65 per cent. 3.10 per cent. 



Phosphoric acid (P0O5) .146 " .70 



Potash {K2O) .475 '■ 2.28 



Water 79.15 



Compared with clover, the fertilizer value is high. The following ar<* 

 summaries of several analyses of red clover: 



Dry substance. 



Nitrogen .2.05 per cent. 



Phosphoric acid .66 " 



Potash 2.24 



SUBSTITUTES FOR GLASS IN GREENHOUSE ROOFS. 



There is much inquiry for some cheap substitute for glass for green- 

 houses, and various preservative preparations are recommended for the 

 treatment of cloth and paper to be used in roofing. We have tried paper 

 one season and cloth two seasons, and find both to be entirely unsatisfac- 

 tory for a winter roof in this climate. They are cold, dark, and not durable 

 For summer or late spring use, oiled muslin is fairly satisfactory. Plants 

 which require a heavy shade in summer can be y:i-own to advantage under 

 such a roof. In the summer of 1891 we found a cloth-roofed house to be 

 an excellent place for flowering the tuberous begonias. Cloth roofs, with 

 ordinary oil treatment, last less than a year, and paper is so easily torn 

 and punctured by drifting twigs that we consider it nearly useless for 

 roofs. It will also tear after a short time by a heavy wind from the inside 

 if a door or ventilator chances to be open. The cost of a few annual roofs 

 of this character will pay for a glass roof. Even if the cloth were to last 

 for two or three years, it would soon become very dark from a collection of 

 dirt and the growth of mildew. 



Our first experience with these covers was the use of paper in the fall of 



1890. The paper used was a thin, white, stiff, architect's drafting paper 

 known in the trade as " Economy." This was laid over the sash-bars and 

 was held down by the caps used for holding butted glass. It was then 

 thoroughly saturated with raw linseed oil. It had been in place but a 

 short time when an ambitious cat attempted to walk over it, and made a 

 hole at about every other step. After a few weeks of vexation, the paper 

 was removed, and a medium quality of unbleached muslin cloth was sub- 

 stituted, being laid on in the same way. This muslin was oiled twice with 

 raw linseed oil. This was in December. The cloth lasted until late 

 spring, but became very black and dirty toward the last. In the fall of 



1891, another covering of the same muslin was laid, and this received 

 three coats of raw oil. This lasted until the next summer. 



This roof is now covered with glass. 



L. H. BAILEY. 



