STRUCTURES ADAPTED TO PARTICULAR PURPOSES. 47 



Fig. 10 is a representation of an ordinary dung-bed, with the 

 frame set on it. The formation of dung-beds is so simple as 

 hardly to need a single word of explanation ; nevertheless, a 

 few passing remarks may be useful to the uninitiated. 



Hot-beds of fermenting materials are generally laid on the 

 surface of the ground. Some prefer the basis of the bed to in- 

 cline slightly towards the horizon ; but we can see no utility 

 whatever in this system, except the site of the bed be very wet, 

 and then we prefer building the bed on a layer of brushwood. 

 It is also beneficial to place a layer of brushwood every eight or 

 ten inches deep, which lets the rank heat and steam escape 

 more readily. The bed should have a slight inclination towards 

 the south, when the frame is laid, though this rather tends to 

 prevent the bed heating equally all over; and, where light is 

 not an object, as in cutting-beds, &c., we prefer it quite level, 

 and even inclining towards the north, the inclination of the 

 frame turned in the same direction. 



Temporary or portable frames, or cases, for covering beds, 

 and protecting plants, are exceedingly useful about places where 

 it is requisite to harden young plants, or protect individual 

 specimens in the open ground. 



Fig. 11 shows a portable glass frame, of a rectangular shape, 

 and which we have often found useful for hardening young 

 stock, in the early part of summer, which was intended for bed- 

 ding out in the flower-garden. It can also be set on a dung- 

 bed for growing early melons, cucumbers, and starting young 

 plants into growth ; for this it is admirably adapted, as the light 

 is admissible all round. 



A portable frame of this kind may be made of any size. We 

 find, however, that about four feet wide, and six or eight feet 

 long, is the most convenient size for practical purposes. 



Fig. 12, the portable plant protector, which will be found 

 exceedingly useful for covering individual plants, standing in 

 the open ground. Those may be glazed with coarse glass, or 

 covered with oil-cloth. They will be found of much utility in 

 covering the more tender conefirs during winter, as well as dur- 

 ing summer from the intense heat. By having the south side of 

 the case painted with a slight coat of a lime solution, to darken 

 5 



