On Straw Mats for covering Hot-houses. 169 



house. The other ring is merely for the purpose of securing 

 the lower end of the mat to the front sill, or otherwise fastening 

 it when drawn over the roof. When the mats are removed 

 from the roof, and rolled up during the day, the cord is loosened 

 from the ring, and lies on the roof, ready to be refastened to 

 it, to draw the mats up next evening. 



In using these mats on hot-houses, each mat is drawn up 

 from the front of the glass to the top of the roof by the cord 

 mentioned, and the end of that cord is made fast to a ring in 

 the front sill ; to which ring also the other or lower extremity 

 of the mat is fixed. The edges of the mats meet one another 

 over the rafters, but do not overlap ; and they are so very 

 light, that they may be drawn up and drawn down in an in- 

 credibly short time. These mats may also be drawn up in a 

 direction across the glass sashes, by attaching a cord to one 

 corner of each end, passing these cords over two pulleys ; and, 

 in that case, the mats might be laid like tiles on a roolj and 

 the direction of the straw would better throw off the rain : but 

 the mode first described, and which is generally used, is the 

 simplest, and has the advantage of being worked by one man, 

 whereas the other cannot be worked without two, or at least 

 not very easily. 



I fear this description will be considered tedious, and per- 

 haps not so clear as might be wished; but no agricultural 

 labourer will find any difficulty in making such matSj when 

 given to understand for what purpose they are to be used. 



1 have more than once had recourse to these mats as a pro 

 tection from hail in the daytime, and occasionally for shading 

 newly shifted pines. I am happy to see that they are begin- 

 ning to be adopted in some of the nurseries and market-gar- 

 dens, and have little doubt that, as the merits of this very 

 simple and economical mode of preserving heat come to be 

 known, straw coverings will be universal in kitchen-gardens. 

 The new system of heating by water, and the revival of this 

 old system of covering with straw or reeds, I consider to be 

 the greatest improvements that have been introduced into the 

 forcing department in my time. 



I am, Sir, &c. 

 Gwmersbury House, May, 1827. Wm. Johnston Shennan. 



We can most strongly recommend the straw coverings as 

 in many cases far preferable to mats or canvass. They are 

 iised at Henderson's nursery, Edgeware Road, the Clapton 

 nursery, Ronalds's nursery, Brentford, and in the botanic 

 garden at Kew. Mr. Shennan has left Gunnersbury, in con- 



