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on one stem, and an Apple on a Cole wort stock. In the high- 

 est department of onr Art improvcmant continual and continu. 

 ing is not wanting, p'orcing which we have seen arose under 

 the Emperors of Rome, and was revived in England about tiie 

 time Parkinson lived, has ever since gradually advanced towards 

 perfection ; for perfection in forcing is obtaining the fruits of 

 warm climates in as great a state of excellence in those which 

 are colder as when cultivated in their native soils. Though on 

 common Ilot-beds Bell Glasses were sometimes used in Park- 

 inson's time, yet the usual protection for plants forced upon 

 them was simply straw, or mats supported from them by sticks. 

 Evelyn more than fifty years after mentions no other protection 

 than Bell Glasses. In the sixth edition of the Complete Gar- 

 dener in 1717, London and Wise mentions no other more 

 extensive protection ; but IMr. Lawrence in 1723, in the third 

 edition of his Gentleman's Recreation, makes mention of 

 Frames, for the purpose of recording an improvement, without 

 alluding to them as a late invention. The improvement he 

 mentions, is having a fixed wire bottom to the frame, which being 

 filled with the earth may be moved to a fresh hot-bed when the 

 heat declines in the first, or whilst any necessary stirring, &c. 

 of the Dung is being performed. Pits of various forms have 

 been invented since. Another improvement for the constant 

 supply of fresh Air to plants in Frames, was by the celebrated 

 Dr. Hales in 1741, on the principal that warm air ascends. A 

 pipe bent in the form of the letter L. is buried in the dung of 

 the bed, with one orifice communicating with the exterior air, 

 the other open in the frame, at the top of the frame a hole is 

 bored with an Augur, the impure heated air is constantly flow- 

 ing from this, and fresh warmed air is constantly rising through 

 the pipe to supply its place. The next improvement worthy of 

 notice was proposed by Mr. Knight, P. H. S. in 1B09. It 

 consists of having the sides of the frame of an equal height all 

 round, and building the bed with the requisite slop;), thus pre- 

 senting every part of the contaioed plants at an equal distance 

 to the glass. U A 



