GLASS STRUCTURES AND APPLIANCES. 



47 



tion in windy weather by placing a pebble or other 

 stone or weight on the top of it. These partially 

 transparent pots proved very efficient protectors, 

 with far more cold-resisting powers than either 

 cloches or hand-lights. 



This probably led the late Mr. Rendle, the author 

 of the tank system of heating — and now chiefly 

 known in connection with a new method of dry 

 glazing — to his successful attempts to combine the 

 cold-resisting qualities of earthenware with the 

 transparent properties of glass in a new and more 

 ambitious method of protecting fruits, flowers, and 

 vegetables in the open air. Hollow or solid tiles 

 were used for the sides, which could be built up of 

 any height, finishing with a groove on the inner 



side of the top tile for the reception of a square of 

 stout glass. This system enables areas of any needed 

 size to be enclosed with the utmost facility and 

 safety. 



The system has now been in use for some years, 

 and though it has not superseded bell-glasses nor 

 cloches, has proved most useful in the culture and 

 protection of salads, the earlier maturation of French 

 Beans and Tomatoes, the growth of Cucumbers, the 

 forwarding of bulbs and other spring flowers, the 

 efiicient protection of Plum and other cordon fruit- 

 trees, and even the growth of Vines in the open 

 air (see Fig. 9) . 



For most purposes the tiles are merely straight or 

 hollow ones, terminated with a groove upon their 

 upper edge (Fig. 8), which are admirably adapted 

 for the protection of Cauliflowers or the culture of 

 Lettuces or other salad plants. The hollow tiles 

 are certainly lighter, and are said to be warmer than 

 the solid ones. 



Fig. 8 gives a full illustration of those most use- 

 ful appliances, and explains how the stout square of 

 glass is fitted into the groove of the tiles ; it also 



shows the glass overlapping where it joins, thus 

 making the whole almost waterproof. 



It is obvious that, by heightening the sides and 

 increasing the width, sufficient area may be provided 

 for the culture of Eoses, fruit-trees, dwarf shrubs. 

 Peas, French Beans, or other plants or flowers. In 

 such cases bricks on the flat do well for the base, 

 the groove-tiles being merely reserved for the top. 



Of course, as the area is extended, the strength of 

 the glass must also be increased, to enable it to bear 

 the weight and wear-and-tear of use ; but the most 

 useful sizes range from four to twelve inches deep in 

 front, from six to twenty-four at back, and from 

 nine to thirty in width. 



By curving the back tile in the form of a C, as in 



Fig. 9, more space, as well as more warmth, is pro- 

 vided. These have been used most successfully for 

 the growth and ripening of Grape-vines, and, as 

 already remarked, are equally well adapted for the 

 protection and successful cultivation of cordon fruit- 

 trees, Marechal Niel, and other rather tender Roses. 

 Fig. 10 is a special protector, not unlike a section of 

 a large sewage or water-pipe, only that it is fur- 

 nished around a considerable portion of its upper 

 side with a groove for the reception of a square of 

 glass ; being, in fact, a great improvement on the 

 inverted flower-pots with their bottoms knocked out, 

 already adverted to. This is a most useful form for 

 placing over tender trees, shrubs, or other plants, 

 such as Fuchsias, Tree Peonies, Hydrangeas, &c., to 

 carry them safely through ' severe winters in cold 

 localities. This form is also admirably adapted for 

 placing over the crowns of Rhubarb in the open, 

 after the more severe frosts of the spring have passed 

 away. The heat of the sun passes freely through 

 the glass, and that heat is retained by the thick 

 earthenware case, the result being a rapid produc- 

 tion of edible produce. One great advantage of 



Fig. 9.— Large Protector for Vice or Cordon Fruit-trees. 



