246 



JOUBNAL OF HOBTICULTUEE AND COTTAGE GAEDENEE. 



[ September 26, 1872. 



protection in spring. Every mode lias its own peculiar advan- 

 tages and disadvantages. 



I am also asked about drying the base of these succulent 

 cuttings for twenty-four hours before planting them. Well, 

 one may just please himself. I have tried the plan again and 

 again, but I do not like the time that thus passes. Even with 

 Milkworts, as Euphorbias, I prefer sticking the ends into 

 powdered lime and sand, instead of allowing them to lie long. 

 In the case of Geraniums I used to slightly shade the tops, 

 whilst the cut end was exposed. Of late years I have inserted | 

 the cuttings as soon as made and roughly sorted into sizes. 



Another question is, Whether they will do best in the open air, 

 or with old sashes, frames, &a., over them? At the beginning 

 of August I would prefer the open air, and if the foliage be 

 reduced the cuttings will stand a great amount of sun. After i 

 the middle of September a little protection will help them, 

 such as will throw off heavy rains. 



The fifth inquiry was answered lately. " Whether prick-out ■ 

 in a border and lift, or prick-out into boxes and pots at once." 

 On the whule I prefer the latter. Any tendency to free growth 

 can be neutralised by comparative dryness, and when lifted 

 and repotted there is generally plenty of withered-leaf-picking 

 afterwards. — B. F. 



BOILERS AT THE ROYAL HORTICULTURAL 

 SOCIETY'S BIRMINGHAM EXHIBITION. 

 No. 2. 

 In continuing our remarks on the boilers at Birmingham, we 

 some next to the horizontal tubulars, of which there were three, 

 exhibited respectively by Mr. Truss, Friar Street, Southwark 

 Bridge Boad; Mr. Messenger, of Loughborough; and Messrs. 

 Dennis & Co., of Chelmsford, the last of which only was for com- 

 petition. 



lower series by means of a syphon. In the larger sizes of boilers 

 hollow triangular-shaped furnace-bars are also introduced, 

 through which all the water has to pass. 



This boiler is no doubt a powerful one, but as the water has to 

 traverse so much horizontal space, and as the flow-pipe is put 

 at one end, the circulation will be much checked. This is a 

 fault, however, common to all horizontal tubular boilers, and 

 where a series of houses has to be heated from a large boiler, it 

 is a matter of great importance ; as if the circulation through the 

 boiler is impeded, even though the tubes are so placed as to 

 extract a great deal of heat from the fire, still those houses 

 which are heated by the pipes furthest from the boiler require 

 a proportionate degree more piping in order to keep up the heat, 

 as the slower the circulation the greater the difference between 

 the heat of the flow and return pipes, and the greater the quan- 

 tity of piping required in those houses which are heated by the 

 return pipes. 



The next boiler we notice is a portable tubular boiler of Mr. 

 Truss's. Truss's horizontal tubular boiler resembles a saddle 

 boiler when covered with its external casing. Both the front 

 and back are hollow, forming water-chambers, which are con- 

 nected together by horizontal tubes, in the largestsized boiler 

 we saw twenty-four in number. The water entering by the 

 return finds a stop halfway up the chamber, and is consequently 

 compelled to traverse the lower pipes before passing into the 

 other chamber, and thence by the upper tubes to the flow-pipe. 

 The tubes where they join the front and back are made to butt 

 against indiarubber prepared by a patented process, "which is 

 said to render it practically indestructible, and further, Portland 

 cement is used to prevent leakage. It is claimed for this boiler 

 that, owing to the indiarubber allowing for the expansion of the 

 tubes, there is no danger of cracking. 



The only horizontal tubular boiler entered for competition 

 was one by T. H. P. Dennis & Co., Anchor Iron Works, Chelms- 

 ford. In this boiler a series of tubular pipes are arranged in the 

 form of a rectangular pyramid or cone, the tubes being con- 

 nected with an upright rising shaft or tube at each of the four 



Mr. Messenger's boiler, of which fig. 1 is an illustration, con- 

 sists of paraUel triangular tubes, with continuous water-spaces 

 at each end. There are two sets of tubes, the lower ones being 

 arranged in the form of a saddle boiler, leaving two horizontal 

 openings on each side between two rows of pipes for the fire 

 and gaseous products of combustion to pass through, which is 

 then made to pass under and over another series of longitudinal 

 triangular tubes laid flat, and which are connected with the 



corners. There are two flows and two returns on the opposite 

 sides of the under and upper rows of pipes. The fire plays 

 through and aB round the pipes, which are set at a little dis- 

 tance from each other. In this boiler much of the check to 

 circulation which is common to many horizontal boilers is ob- 

 viated by the four upright tubes at the corners, the length of 



j the horizontal tubes being reduced very much at the upper part 

 of the boiler, and the water has free ingress or egress at each 



I end of the. pip3s, and need not necessarily traverse the whole 



I length. 



