274 



J0UI»5AL OF HOBTICDLTDKE AND COTTAGE GABDENER. 



[ AprU IS, 1871. 



occnrs at that place, mB.Wng no less than thirtj-one species in the open 

 air there. 



Phylloxera vastateix, the insect which is so alarming Enropean 

 Vine growers, is said to be an introduction from the United States, but 

 it appears more is laid to its charge than it deserves. Another, Dac- 

 tylopius longispinis of Targioni, II. Planchon says, is the cause of the 

 " Blaek evil " (maladie noire) in the Grape Vine. 



Botany in Africa. — They have a thriving Botanic garden at Natal. 

 Mr. McKean is the director. They have just started a Society of 

 Natural History. Its first publication gives much attention to botany. 

 A new climbing Scrophulariaceous plant, to which order our well-known 

 Maurandya Barclayana belongs, is described in it, under the name of 

 Bnttonia natalensis. 



The American area of Grapes has been put at 2,000,000 acres, 

 of which California claims 200,000, or one-tenth of the whole. 



Stamens and Pistils of the Grape Vine. — There are three 

 distinct kinds of flowers on the Grape Vine. Some time since, Dr. 

 Engelman wrote to us to know if any one had ever seen a purely pistil- 

 late Grape. He never had. "We now think it does not exist. But 

 there are certainly three forms : — First, purely staminate, in which 

 there are no trace of the ovarinm ; secondly, small ovaries, with defective 

 stamens, which never produce seeds, though often swelling enough to 

 make small Grapes with no seeds ; thirdly, hermaphrodite, which we 

 believe alone produces fruit. "We suspect all the male flowers throw 

 their efforts away. 



CANNELL'S REGISTERED ECOXOMISING 

 BOILER. 



The long sharp weather of last winter, and the immense 

 consumption of fuel to keep up the necessary temperature to 

 preserve my plants, caused me to ponder mnch about heating 

 our horticultural buildings, and at the same time to see if it 

 was not possible to utilise the great amount of heat which has 

 been up to the present time allowed to escape by the chimney. 

 I determined to put my ideas together, and see if I could not 

 combine all the qualities that a boiler should possess, and the 

 annexed engravings, and the following particulars will show 

 how I have succeeded. 



Fig. 1. 



The boiler [fig. 1) consists of nine or more separate hollow cast- 

 ings, placed one upon another. Upon brickwork is placed the 

 basement or No. 1 casting, consisting of a hollow rectangular 

 frame, into which are fixed eight (more or less, according to the 

 size of boiler) circular hollow fire-bare, placed at such a distance 

 from one another as to allow sufficient space for the draught. 

 At the back or further end of this casting are the return pipes, 

 and in the front the discharge pipe for cleansing the interior of 

 the boiler at any time. The ashpit is formed by the brickwork 

 supporting the first or basement casting, and is enclosed by a 

 door hung on a solid cast-iron frame built into the brickwork or 

 otherwise. The furnace door is to be hung in the same way. 



Upon the first casting are placed four other separate hollow 

 castings, of which Nos. 2 and 3, forming the sides of the fur- 

 nace, are fiuted and placed parallel with the hollow fire-bars, 

 and are of such a length that the two remaining castings, Nos. 

 4 and 5, which form respectively the back and front of the ap- 

 paratus, may be flush with the ends of the first castings. The 

 back, or No. 4 casting, is large enough to cover the whole or 

 part of the end of the apparatus, and is connected at the bottom 



by pipes with castings Nos. 2 and 3 respectively, and at the top 

 on each side with casting No 11, which will be afterwards de- 

 scribed. The front casting. No. 5, must be of such a height 

 that the top will be level with the top of No. 6, forming the top 

 of the furnace. 



The front is built up with brickwork, with three sliding soot 

 doors to allow the fines to be properly cleaned out. This front, 

 or No. 5 casting, is connected at the bottom by pipes with cast- 

 ings Nos. 2 and 3, and at the top on each side with casting 

 No. 6. Upon the top of castings Nos. 2 and 3 is placed a sixtli 

 further and separate hollow fluted casting, forming the top of 

 the furnace, having a space left at the back opening upwards, 

 to allow a free passage for the flre to pass out of the furnace 

 under a separate and hollow casting (No. 7), which when fixed 

 forms two flues communicating, by means o£ other flues formed 

 by similar castings, and terminating in a rectangular opening 

 at the top for regulating the draught, and for the passage of 

 the smoke into the chimney. 



The circulation of the water from and into every separate 

 hollow casting is effected by means of four sets of pipes affixed 

 externally to the castings, two sets being placed on each side of 

 the apparatus. If desired the crown or top casting with the 

 flow-pipe can be placed upon No. 2 or 3 casting, and worked 

 without the flues until required. The fiarae or hot air from 

 the fire placed on the hollow bars will pass between castings 

 Nos. 2 and 3, until it arrives at the opening, described to be left 

 at the back of casting No. 6, where it will divide, and pass 

 upwards towards the front through the two flues formed by 

 casting No 7. It will then return towards the back through the 

 two flues formed by casting No. 8, again uniting and passing 

 upwards into the flues formed by castings Nos. 9 and 10, the 

 heat thus continuing to travel through castings Nos. 9, 10, and 

 11 in the same way, so that the hot air wiU pass sis times 

 through the internal length of the apparatus before escaping 

 into the chimney. 



It will therefore be seen that this boiler is so constructed 

 that all the caloric which the fuel contains is extracted and 



Boiler. 



conveyed to the water, only just sufficient to take away the 

 smoke being allowed to escape. Any length of flue can be 

 added, or the boiler can be worked without any flue at all ; and 

 as the glass houses or buildings are extended so can heating 

 power be added. It requires no brickwork beyond its founda- 

 tion to form the ash-pit, and a wall round, as in almost all 

 stoke-holes, to form a frontage; the latter can, however, be 

 dispensed with. There are no dead-plates, solid bars, or bricks 

 in this, as in most other boilers, to burn and crack, thereby 

 admitting a quantity of cold air which tends to cool the water 

 instead of heating it. 



In order that there may be confidence in a boiler, there mns 

 be uniform strength in the castings. It is well known that the 

 more complicated the castings the more difficult is it to procure 

 an equal thickness, while inequality causes unequal expansion 

 and contraction, and occasions fractures and leakages. But in 

 my boiler all the parts are in square sections, and easily cast ; 

 consequently a regular thickness can be guaranteed. Any of 

 the compartments can be renewed or replaced without destroy- 

 ing the remaining parts, as the boiler is made in sections, and 



