CULTIVATION OF THE GEAPE UNDER GLASS. 141 



eigMeen inches below th.e plate. There should be a Ventilator 



in each space between the rafters. The easiest arrangement for 



opening and closing them, is to swing them on a pivot, with a 



curved iron rod running from the edge of each ventilator and 



fastened securely to a larger rod, which is run the whole length 



of the house, and which is supported on brackets fastened in the 



wall and standing out about three inches from the face of the 



wall. This long rod is very readily and cheaply obtained by 



using inch gas pipe. At one end of this long rod, and running 



at right angles to it, is fastened a rod or bar to act as a lever ia 



turning the long rod on its axis. From the end of this lever 



depends a handle, which is pierced at the lower extremity with 



numerous holes. When it is desired to open the ventilators at 



the top of the house, tiiey are aU openened simultaneously and 



to any desired height, by means of this handle, which actiug 



upon the lever turns the long rod, and this turning of the rod 



pushes open the ventilators. These are kept open to any desired 



degree by slipping the lower end of the handle on to a peg fixed 



iu the wall, which passes through any one of the several holes 



with which the lower end is perforated. 



A good mode of building is to put up a frame, fill ia between 



the studs with brick laid ia mortar, making a four inch wall, 



and then plaster on the brick. All the interior of the house 



should be made as smooth as possible, and the wood work well 



painted, so that the house may be thorougly cleansed every year, 



and leave no hiding place for insects. The roof should be fixed, 



the astragals reaching from the plate to the ridge, and the 



glass bedded in putty, with a lap of not more than one-eighih 



down to one-sixteenth of an inch. If pieces of tin, four inches 



wide, be first laid for the bottom course, and then the glass laid 



on, lapping the eighth of an inch on the tin, it wiU be found a 



saving of glass in frosty weather. The rafters should be two by 



six inches, placed three feet ten inches apart, from centre to 



centre, and a vine trained under each rafter. Across the upper 



side of the rafters, and about midway of their length, should run 

 11 



