32 GREENHOUSES 



designed to cover two sash and should be 

 6x7 feet to allow for turning over the ends 

 of the sash to keep out the wind. An ob- 

 jection to straw mats is their weight, especi- 

 ally when wet, and also the fact that mice are 

 likely to work in them while they are stored 

 during the summer. With careful handling 

 they will last three or four years. 



Fig. 18. Hot-bed covered with (C) double glass sash; 



(B) sash and straw mat; (A) sash, straw mat and 



shutter 



Burlap and Canvas Mats, which are pad- 

 ded with waste cotton and quilted, are easier 

 to handle than straw mats and are somewhat 

 more durable. Though usually thinner than 

 straw mats, they give practically as good 

 protection. They have the added advantage 

 of requiring less storage space, and are some- 



