204 Substitute for Hand-Glasses, 



America. The tree, however, thrives vi'ell in the climate of 

 Paris, as appears by specimens in M. Vilmorin's grounds at 

 Verrieres. Q. tinctoria Willd. is next to Q. rubra in point of 

 vigorous growth, and is expected to save France several millions 

 sent to America for its bark. 



(To be continued.) 



Art. II. A Substitute for Hand-Glasses, and a more economical 

 Mode of using Glass in Forcing- Houses suggested. By A. 

 Forsyth. 



I HAVE often felt sorry in passing by some spirited amateur's 

 garden, to see his little lean-to roofed hothouse glazed up to 

 the apex, with two glazed gable ends, and a yard or more of 

 upright glass in front. If this gentleman is rich enough to be 

 possessed of two hothouses, you generally find them in separate 

 compartments of the garden, with glazed doors in the glazed 

 gable ends of each ; or, if by any chance they do adjoin, you 

 may rely upon finding them divided by a glazed partition. I 

 wonder these schemers never thought of glazing the back wall to 

 catch the northern lights, not only the aurora borealis, but also 

 " the rays of the bright polar star : " the first is certainly a very 

 fickle and capricious source of light, and far from fervent; and 

 the polar star, though a shining light, is not by any means a 

 burning one, yet makes amends for the feebleness of its beams 

 by the constancy of its services : for, though the sun himself 

 may vary, and the moon change, the polar star will assuredly 

 face the frosty north, like the point of the magnetic needle, day 

 and night, alone and unalterable, amid the mutability of all 

 things sublunary and celestial. However ridiculous this foolery 

 may appear of glazing the dead north wall, it cannot be denied 

 that in the shape of hand-glasses it is practised to the fullest 

 extent in almost every garden in Britain. 



Before I enter upon the immediate subject of this paper, allow 

 me to remind the proprietors of such houses as those above de- 

 scribed, that they have used as much materials to make one bad 

 hothouse as would with judicious arrangement have made two 

 good ones of the same size : but, as 1 have already written on 

 this subject [Gardener's Magazine, vol. xvi. p. 229.), I need not 

 now repeat what I have said. The actual measurement of a 

 common square hand-glass is seven square feet of glass to light 

 and shelter two and one fourth square feet of ground, being a 

 little more than three tirrues as much as is really necessary; for 

 I think few will dispute that cucumber or cauliflower plants, 

 when they happen to be placed in a common melon frame (the 

 surface of the glass and that of the soil in the frame being nearly 



