182 



THE GARDENER'S. ASSISTANT. 



the aim, but the greatest amount that the sun 

 can shine upon with the fullest effect. 



We may suppose that the roof of a forcing- 

 house is composed of one entire sheet of bright 

 glass, and that between this and. the floor a 

 medium of ground glass is to be interposed 

 where it will transmit the greatest quantity 

 of light. To do this it must be placed where 



Fig. 988.— Early Peach Hrmse. Scale i in. to 1 foot. 



the light or the sun's rays can act through the 

 sheet of glass with the greatest intensity. It 

 must, then, be placed so as to form a plane near 

 to and parallel with the plane of bright glass. 

 The medium of ground glass might be waved 

 to curve away from the glass roof like the 

 circular front trellises which some recommend 

 for the Peach; and having receded consider- 

 ably, it might then curve upwards to the top 

 of the back wall. This curving would require 

 a much greater surface of ground glass than a 

 plane running parallel to the roof; but the 

 light below would be considerably less in the 

 former than in the latter case, because the 

 light after passing through the bright medium 

 would act with diminished intensity on the 

 portion of ground glass situated at a distance 

 from it. If we take a lens and hold it near 

 the glass of a forcing-house when the sun is 

 shining, touch-paper will be readily ignited; 

 but it will not be so if the lens is held at a 

 distance from the glass. 



If curved trellis work were constructed there 

 would be a greater surface for training, but the 

 amount of the action of the light on the foliage 

 would on the whole be diminished. A distance 

 of from 12 to 15 inches, as already stated, 

 between roof and trellis, answers very well; 

 farther would prove disadvantageous so far as 

 light is concerned, indeed a less distance would 

 be preferable in that respect; 

 but, on the other hand, vege- 

 tation would be injuriously 

 affected in severe weather if 

 brought into closer proxim- 

 ity to the cold glass. 



Fig. 988 shows the form 

 of house for early forcing. 

 Succession houses may be 

 span -roofed, or if lean-to 

 houses are preferred they 

 should be built with flatter 

 roofs than the above, in order 

 that they may be cooler 

 when the fruit is ripening. 



The trees may be planted 

 young, or they may be 

 trained for several years, 

 but in this case they should 

 be taken up and replanted 

 every second year. Their 

 training ought to be con- 

 ducted with a view to the 

 position they are intended 

 to occupy. They should be 

 treated as directed for fan- 

 training in respect to starting the branches. 

 The length of the stem must depend on the 

 height of the trellis from the ground at the 

 place where the trees are to be planted. The 

 stem should be cut over so as to subdivide at 

 the base of the trellis. The branches ought 

 to be trained with an inclination equal to the 

 angle of the roof. By attending to this a tree 

 may be reared to a bearing state before it is 

 introduced under glass. 



The late Mr. Errington, one of the most 

 skilful gardeners in the country, selected the 

 largest, cleanest, and best formed tree on the 

 open wall, where it covered 480 square feet, 

 removed it to a Peach-house, of course with 

 due care, and the tree ripened in the same 

 year about eight dozen of very good fruits. 

 In the succeeding seven years it produced at 

 least 2300 large and fine fruit. Specimens of 

 the fruit we have frequently had the oppor- 

 tunity of seeing, and certainly they were re- 

 markably fine. This is sufficient proof that 



