1879.] HEATING BY HOT WATER. 417 



prepared for the reception of the cuttings, dibhling them in not 

 over closely, and keeping the lights on and shaded from sun for a 

 few days ; afterwards the sashes may be dispensed with, and the 

 plants allowed to make a good start before potting them up. The 

 compost should be a rich one, say three parts strong loam to one 

 part of dry cow-dung, with a sprinkling of bone-dust and sand added. 

 The plants may be put into their blooming-pots at once, making 

 the drainage sure, and potting firmly. The plants will do well 

 out of doors until October, when a place near the glass, in a structure 

 where they will be kept gently growing throughout the winter, will 

 suit them best. "When the pots get filled with roots, manure-water 

 will be required at every time of watering, otherwise the plants 

 will get stunted and stop growing. As spring advances, air will 

 require to be freely given until the plants are opening their flowers, 

 when they are taken to the show-house or conservatory. We have 

 grown Pelargoniums in small pots for years, and can vouch for the 

 success of the system. Everything, of course, depends on the 

 unceasing care bestowed on the plants throughout the year, for 

 the insuring of complete success. R. P. B. 



HEATING BY HOT WATER. 



Allow me to make a few more remarks on this question, and I am 

 done with it, as I think the matter may now be safely left in the 

 hands of Mr Hammond and his opponents. This I shall do as briefly 

 as possible, making note of only a few extracts taken at random. 

 These are partly side issues, it is true — still we cannot arrive at any 

 just conclusion without considering some of these to a certain extent 

 at least. It will not do to dogmatise on such a matter without show- 

 ing our reasons for and against the several points raised. Mr Ham- 

 mond says it is unnecessary to have the flow-pipe on an ascent 

 throughout its whole length, and he is corroborated by several corre- 

 spondents from apparatus in actual use. The facts, as placed before 

 us in these papers, are worth more than any amount of theoretical 

 rules, some of which, in actual practice, are almost worthless as 

 evidence. 



At p. 325 C. M. says, in answer to Mr Hammond : " The difference 

 of the specific gravity of the two volumes of water is the consequent 

 result of expansion, which must be the primary cause." Is heat not 

 the primary cause, of which expansion is the consequent result 1 This 

 may appear a quibble, but there is a point in it. 



At p. 328 Albion proves the efficiency of the system advocated by 



