46 GARDEN FOES. 



contente of the glas^sliouse «hould be ascertained bef(3re- 

 hand, and either marked up in a spot ea^sily to be found 

 or memoranda thereof entered in a notebook. Most of the 

 nicotine preparations have printed directions on them 

 stating the quantity to be used per 1,000 cubic feet; hence 

 it is essential the exact cubical area of a house to be fumi- 

 gated should be known. To ascertain the cubical contents 

 of a span or lean-to greenhouse, in order to know the 

 exact quantity of fumigating material required, proceed 

 as follows: In the case of a span-roof greenhouse (Fig. 1) 

 multiply the length C to D by the breadth A to B, and 

 the total by the average height, obtained by the aA^erage 

 height B to E, and the result will give the cubical con- 

 tents. Proceed in a similar manner with a lean-to struc- 

 ture (Fig. 2) — that is, multiply the length C to D by 

 the breadth A to B, and the total by the average height 

 B to E. The dotted lines show the directions in which 

 the measurements should be taken. The portions of the 

 loofs above the dotted lines E E are allowed for b^^ assum- 

 ing that the angles of the dotted lines E to B represent 

 space equal to these. 



How to Fumigate.— The best time to fvmiigate a 

 greenhouse or frame is the evening of a calm day. If the 

 day be windy the rush of air through the laps, of the glass 

 or ill-fitting sashes, doors, and ventilators, will drive out 

 the fumes, and the volume of nicotine fumes or vapour 

 will not be sufficiently intense to destroy insect life. Fail- 

 ing a calm evening, choose the early morning of a dull 

 day. In any case, see that the ventilators are tightly 

 closed, and broken glass and crevices sealed up. Damp 

 sacks or mats thrown over broken glass or badly-fitting 

 ventilators, and also placed at the bottoms of the doors, 

 will prevent the fumes or vapour escaping. The foliage, 

 too, of the plants must be dry, and so must the floor and 

 staging, for the nicotine to act effectively. 



Once the materials are started into action, withdraw 

 from the house and lock it up. If fumigated in the even- 



