286 On the Means of supplying 



steaming process is the following, and it is admissible only 

 because steam is no longer employed. A shallow cistern, about 

 6 in. deep, and carryuig at least 4 square feet of area, with a 

 false bottom of wire or pierced zinc about 1 in. from the real 

 bottom, being provided, the steam pipe from the boiler should 

 be introduced, so as to discharge itself between the real and 

 false bottom ; the cistern should now be filled with water 

 nearly to its brim, and the steam laid on. The water will soon 

 be raised to a pretty considerable temperature, and yield an 

 abundant supply of innocuous vapour. This operation may be 

 continued at pleasure, the cistern being filled up as it wastes. 

 Of course, the size of the cistern must be regulated by the 

 size of the house, and my experience is not sufficient to enable 

 me to say what is desirable, but certainly less than 4 square 

 feet w^ould be useless in an ordinary hot-house, say 25 ft. by 

 13 ft. 6 in. 



I may, perhaps, be charged with inconsistency in providing a 

 steaming apparatus to the conical boilers, holding, as I do, such 

 opinions concerning the use of steam. But, under the modifi- 

 cation above described, I can conceive some advantage may 

 be derived from its employment; and I believe it has a ten- 

 dency to destroy insects : moreover, I think it possible that 

 Mr. Beaton's suggestion of employing steam impregnated with 

 tobacco or sulphur might be found advantageous ; so that I 

 was willing to afford those who are favourable to such experi- 

 ments the means of making them. I have a steam pipe to my 

 own boiler, and used occasionally to employ it in the above 

 manner, but often perceived harm, and certainly never could 

 discover any good effect from it; and now having adopted 

 the use of the cisterns above described, I obtain a far more co- 

 pious moisture than I could procure by any quantity of steam, 

 which should not absolutely boil my plants. This moisture is 

 produced just when 1 want it, without trouble. During the sum- 

 mer season, the portable steaming apparatus suggested by Mr. 

 Beaton might be found useful, but always under the form 

 above suggested ; and, even in this case, I believe that a good 

 sprinkling of water over the floor and flues, hot from the 

 heat of the day, would produce the same effect much more 

 safely. In orchideous houses one is seldom without fire even in 

 summer. 



The effect of the zinc cisterns is most satisfactory and natural. 

 At the present season (April 30.), there is a constant fire in my 

 orchideous pit, and of course a copious evaporation from the 

 cisterns. On going into it late in the evening, the plants are 

 found all reeking with an almost tropical dew, and every pore 

 may drink in abundance. In the morning, as the sun's beams be- 

 gin to raise the temperature, this dew disappears ; and, air being 



