General Notices. 563 



to be similar, or perhaps identical, in their nature. The beam, or ray, of light 

 has no sensible heat high up in the atmosphere, and it is only the refraction 

 and reflection of the atmosphere and other bodies which make it sensible. — 

 R. May, 1840. 



Oil-Paper Frames, or hand-frames covered with oil-paper, generate more 

 heat than glass frames, or hand-frames glazed with glass, for reasons which 

 may be deduced from the facts stated in the foregoing paragraph. — Idem. 



The Potting-bench Instrument, I find a most useful article for mixing dif- 

 ferent moulds, and also for potting. The form is such that it will convey 

 mould into the smallest pot. It is made of sheet iron. It is a half-cylinder, 

 with a piece on the top as a brace, and a handle standing up, so as to clear the 

 hand well from the potting-bench ; in a word, if I were to say it is a coal- 

 scuttle in miniature, with a handle at the end, you have a full description of 

 it. Mine is 7 in. long, 2 i in. deep at the handle, and 4 in. over at the top. 

 The handle is 5in. long. The edges of the iron are turned up to make it 

 strong, except the fore part for sliding along the bench. — J. D. Parkes. Dart- 

 ford Nursery, May 12. 1841. 



A Forcing-House ivhich may be applied to various Purposes. — I would have 

 the back part of the house heated by a row of hot-water pipes, the pipes to 

 run along the back of the path ; 1 would have two stop-cocks in the hot- 

 water pipes immediately at their entering the house from the boiler, by which 

 means the water in the pipes could be cut off from that contained in the boiler 

 at pleasure ; at the same time I would insert a pipe in the top of the boiler, 

 and bring it into the house where the hot-water pipes enter, and run it closely 

 under the hot-water pipes. I would have a few holes perforated in this pipe, 

 so that the steam would escape into the house, and thus the boiler would 

 serve two purposes. I feel confident there is nothing better for promoting 

 the growth of pines and cucumbers than steam, if cautiously used. On the 

 top of the hot-water pipes I would have dishes, but the one to be in con- 

 junction with the other, in such a manner, that by a tap running into one dish 

 at the end it would fill the whole of the dishes. 



As to the heating of the front of the house, I would have a trench made for 

 alining of dung, and have boards to fit neatly over the top, so as to keep the 

 dung out of sight. The thickness of the front wall I would have about the 

 length of a brick, and it should be pigeon-holed from top to bottom. I would also 

 have a vacuity inside, betwixt a slate flag and the front wall ; the flag to be 

 about ^ in. in thickness, and built from bottom to nearly the top of the front 

 wall, in order that the heat of the dung might act against it. I would 

 also have one row of ventilators fixed on the slates, so as that I could either 

 admit the steam from the dung into the house or not at pleasure. In some 

 cases the dung might go round all the house, except where the door and 

 boiler might happen to be ; and when the dung was in good order, the fire 

 might be at that time altogether discontinued. All the cucumbers that are 

 grown here are grown in a house ; and I feel confident no one would trou- 

 ble himself with frames, if he saw the great quantity of fruit that is grown 

 here all the year round. — Charles Ewing. Knowlesley Hall Gardens, May 3. 

 1840. 



An Ice-House under Rockwork. — I lately made a piece of rockwork upon 

 a spot that is very limited, where space is of the greatest consequence, and ma- 

 terials to constitute bulk not easily procured. Under these circumstances, I 

 made, as it were, a framework of arches, whereby much useful room was 

 gained, and considerable materials saved. Others so situated may profit by 

 the hint. I do not send a sketch of the ground plan, as the dimensions may 

 be entirely suited to the nature of the spot operated upon. The height 

 within, however, ought not to be less than 7 ft., for the convenience of per- 

 forming any operations that may be necessary. 



Such a place as that represented might, with great propriety, be made the 

 entrance to an ice-well, when the materials excavated would do much towards 

 forming the erection outside. Forming the interior (when convenient) into 



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