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. The book of garden management : Comprising information on laying out and planting Gardening -- Great Britain. GREENHOUSES, HOTHOUSES, FORCING-PITS. 255 endless chain is to work and tm-n the screw, in fact, this is its axis. The handle H is fixed to some convenient place on the front wall, being the mover of the whole apparatus. As the rod is moved from right to left, the short rods push the lights up and admit fresh air as they are acted upon : by reversing the screw, the opposite result is obtained. 689. The ridge-ventilation is obtained in precisely the same manner; tho lights u
. The book of garden management : Comprising information on laying out and planting Gardening -- Great Britain. GREENHOUSES, HOTHOUSES, FORCING-PITS. 255 endless chain is to work and tm-n the screw, in fact, this is its axis. The handle H is fixed to some convenient place on the front wall, being the mover of the whole apparatus. As the rod is moved from right to left, the short rods push the lights up and admit fresh air as they are acted upon : by reversing the screw, the opposite result is obtained. 689. The ridge-ventilation is obtained in precisely the same manner; tho lights under the coping being pushed out or drawn down by turning a handle attached to a long endless chain on the end wall. 690. The result of this system, to use Mr. Messenger's words, are,—1. perfect ventilation; 2. non-interference with the plants; 3. no risk of broken glass by the lights fallen down; 4. keeping out rain when the lights are open. 691. The roof Mr. Messenger makes of very light rafters, only three inches by two, strengthening them by means of a tension-rod placed under each, as shown in the engraving. These are firmly fixed at each end, and kept extended by means of two iron rods fixed in the rafters at equal distances from each other, and from the extremities. Between these rafters sash-bars are placed, which, when glazed and painted, are perfectly waterproof, and extremely light and elegant in appeai-ance; the tension-rods being both graceful, and the rafters light and any, and strong enough for every purpose required. To his other patents, Mr. Messenger has added a new principle of glazing for greenhouse and other roofs which is perfectly waterproof and air-proof also without putty. With this invention the roof may be nearly flat; thus efiecting a great saving in material, no paint being required in connection with it. 692. The system of glazing patented by Mr. Messenger is simple and ''^ ingenious: the upper surface of the sash-bar, of which we give a sect
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Keywords: ., bookauthorbeetonsamue, bookpublisherlondonsobeeton, bookyear1862