188 ON THE CONSTRUCTION OF PEACH-HOUSES. 



down in fine weather, to the point B, every part of the fruit on the trees, 

 which are trained nearly horizontally, along the dotted line C, will receive 

 the full influence of the sun. The upper lights must be moved, as usual, 

 by cords and pulleys ; and if these be let down to the point A, after the 

 fruit on the front trees is gathered, every part of the trees on the back 

 wall will be fully exposed to the sun, at any period of the spring and 

 summer, after the middle of April, without the intervention of the glass. 

 A single fire-place will be sufficient for a house of 50 feet long ; and I 

 believe the foregoing plan and dimensions will be found to combine more 

 advantages than can ever be obtained in a higher or wider house. 



Both the walls and flue must stand on arches, to permit the roots of 

 the trees to extend themselves in every direction, beyond the limits of 

 the walls; for whatever be the more remote causes of mildew, the 

 immediate cause generally appears to be want of moisture beneath the 

 soil, particularly if it be combined with excess of moisture, or dampness, 

 above it. In experiments which I have made to discover the cause of 

 mildew, in other plants, I have found that nothing so effectually prevents 

 its appearance as abundant moisture beneath the soil ; and many gar- 

 deners, who have had the misfortune to cultivate the peach in situations 

 where the roots, at a small depth beneath the soil, were destroyed by 

 water during winter, or where the same effect was produced by the 

 unfavourable nature of the subsoil, must have observed the injurious 

 effects of mildew. 



I shall conclude my paper with observing, that I have never seen the 

 peach in so great a state of perfection, as when cultivated very nearly 

 according to the preceding directions : and I estimate so highly the 

 advantages of bringing forward the fruit under glass, till it is nearly full- 

 grown, and then exposing it to the stronger stimulus of sunshine, without 

 the intervention of the glass, and excluding it from rain and dews, that I 

 believe the peach might be thus ripened in greater perfection at St. 

 Petersburg, in a house properly adapted to the latitude of that place, 

 than in the open air at Rome or Naples. 



