September 2G, 1872. ] 



JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 



217 



We in common -with many others regret that a frill report of 

 the boiler trials at Birmingham has not been published, as it 

 "would be of great interest to the horticultural world ; and al- 

 though the trial was conducted under many adverse conditions, 

 yet the summary of results arrived at would give much insight 

 into the relative rapidity of circulation in different boilers. 



"We pass on next to a boiler entered for competition by Mr. S. 

 Deard, of Harlow, Essex, and which deserves very honourable 

 mention, as having the truest circulation of any boiler yet con- 

 structed. The large one exhibited by Mr. Deard was the first 

 one ever made. The boiler is on the principle of a spiral pipe, 

 the pipes in the boiler being of the same diameter as the pipes 

 to be heated. The boiler is formed of close coils of cast iron 

 pipes formed in half-segments of circles continuously jointed 

 together by cast iron clips. At each end of the semicircular 

 segments is cast a screw ; the two segments of the circle are 

 placed together, being previously turned and planed to a true 

 surface, and the clips are cast on the pipes, so as to make a solid 

 connected spiral coil (fig. 2). A T-piece is inserted in the lower 

 part of the return pipe for the purpose of removing sediment 

 when necessary. The boiler is fed by a furnace from the bottom 

 and not from the top as most tubular boilers are, and so will 

 burn any kind of fuel. The coils are set close, and, conse- 

 quently, the patentee is enabled to put flues on the exterior by 

 means of six cast iron flange plates, which are made to fit the 

 •coils of the boiler, and are inserted in the surrounded masonry, 

 and the products of combustion are thus made to play up and 

 down on the exterior surface of the boiler. We noticed that at 

 Birmingham the boiler was tried at a disadvantage, as the flange 

 'plates were not there in time, and the separation between the 

 flues had to be made by means of bricks, with a loss of heating 

 surface represented by the comparative thickness of six rows of 

 3> ricks or six thicknesses of iron plate. We think the apparatus 

 •deserving of great commendation, and in the hands of the in- 

 ventor will turn out a very efficient boiler. 



The same exhibitor had at work in an adjoining stand a small 



Kg. 8. 



centrifugal heating apparatus, of which we give an illustration, 

 and which obtained a bronze medal for its efficiency. 



This combined stove and hot-water apparatus might be used 

 with great advantage in a hall or corridor, the pipes being taken 

 to- heat an adjoining greenhouse. By means of proper dampers 

 and regulators both in the chimney aud ash-box either slow or 

 rapid combustion may be set up, and the whole stove might be 

 used inside the conservatory, as, if the coil pipe were made to 

 surround the whole of the fire, there would be no fear of air 

 being burnt by red-hot iron. The same boiler might be heated 

 by means of gas, air to regulate combustion being supplied in 

 ■each case by an outside pipe. 



Gur next notice will include the saddle boilers and modifi- 

 cations of saddle boilers, as tank, conical, and cylindrical boilers, 

 though as there were so many exhibited we fear we cannot give 

 a full description of all. Those of the competitors who made 

 notes of their own boiler trials are requested to forward the same 

 to the office. We have already notes of two. We do not neces- 

 sarily intend to publish them. 



CONIFEBS AT LINTON PABK. 



I beg to thank Mr. Fleming for having, at page 205, given us 

 the dimensions of some of the important Conifers at Dropmore, 

 as we are thus enabled to compare notes and to see how far our 

 specimens are behind those in the much-famed Dropmore col- 

 lection. With the exception of Bicton there is no place where 

 this class of plants has been so extensively cultivated as at 

 Dropmore, and I am not sure that some of the specimens there 

 do not exceed those in its rival's more favoured climate. I now 



purpose giving such short notes on some of the specimens here 

 as will enable the reader to judge of their growth. 



Pinus insignis, planted 1844, is now 64 feet 6 inches high, 

 feathered to the ground. The diameter of the branches is 

 51 feet, and the girth of the bole at 4 feet up, as taken at the 

 most slender part between the branches, is 8 feet 2 inches. This 

 tree, I may observe, lost its leader about 1848, and remained 

 three years without one. Since then its growth has been very 

 rapid. It did not sivffer in the least in the winter of 1860-61, 

 and but very slightly (hardly perceptibly), in that of 1866-67 ; 

 although another specimen of the same kind not so large then 

 suffered much. It is a fine tree, has coned for many years, but 

 since it commenced doing so and producing the catkins which 

 precede the cone, it has to a certain extent lost that deep 

 emerald green which gave it so important a character when 

 about 30 feet high. I find this is also the case with other young 

 trees of the same species. Although the tree referred to is in 

 the best possible health, it is not of so fine a green as it once 

 was, and a specimen of P. austriaca near it that was once its 

 inferior in that respect, is now its equal if both are looked at 

 from a distance of 100 yards off. I may remark that P. insignis 

 exceeds in size any of the Scotch or Silver Firs that were planted 

 as a screen, and as nurses to the pinetum. To show that this 

 rapid growth is not confined to the tree alluded to, I may state 

 that one planted in 1855 is now 46 feet 6 inches high, feathered 

 to the ground, healthy, and vigorous ; while others planted at 

 the same time are nearly as large. 



Pinus pondebosa. — As Mr. Fleming does not mention this, 

 I apprehend the tree is either not a good specimen or is con- 

 founded with P. macrocarpa. Here, however, it is the finest 

 of the long-leaved species, the average length of the leaves being 

 10 inches with three in a sheath ; the general hue of the tree a 

 darker green than the Scotch Fir, although not so much so as 

 P. inBignis. In many places fault is found with it for its lack of 

 foliage, and the decaying leaves being persistent ; here the latter 

 charge is unfounded, for as the tree is healthy and vigorous it 

 throws off its decaying foliage, and its naked and formidable 

 limbs stand out boldly, each with a dense tuft of most sturdy 

 foliage at the end. Our tree is 55 feet high, and retains most of 

 its branches from the ground, but as they chiefly point upwards 

 it has not the dense habit of P. insignis. It was planted in 

 1844, and has only once shown symptoms of coning. It is 

 a noble and deserving tree, quite equal to P. Benthamiana, of 

 which, however, we have not a large specimen. 



Pinus austriaca, 54 feet 6 inches high and feathered to the 

 ground, but more cylindrical in shape than most others. This 

 was also planted in 1844, is a fine tree, and from what I have 

 seen of it elsewhere, seems to be one of the most desirable of 

 its class. Its deep green hue and upright timber-like bole re- 

 commend it alike for use and ornament; and I have seen it 

 thrive well on very poor ground. In a young state it is very 

 bushy, but, in fact, most other Pinuses of a similar kind are thus 

 in their early growth. 



Pinus excelsa. — Upwards of 40 feet high, and quite 55 feet 

 in the spread of its branches, forming, in fact, an immense bush 

 of dwarf conical form ; for it starts with a decided leader. There 

 appear to be two varieties of this, or it may be that they are 

 two distinct species, one of them having its spring buds enclosed 

 in scales of a bright rosy pink colour; the other one plain green, 

 there being no perceptible difference in colour, habit, or 

 character of foliage. Both bear very long cones of a purplish 

 colour, and hanging downwards ; occasionally the cones are in 

 pairs, but oftener are produced singly. The rich silvery grey 

 foliage is in a great measure pendulous ; and differing as it 

 does from most other Pinuses in its glaucous hue, this species 

 is of great value in a collection ; it is also hardier than many 

 kinds. Our tree was planted in 1844. 



Pinus Cembba, 54 feet 6 inches high, was probably planted 

 about 1835. It is a pretty cylindrical rather than a conical form, 

 and has leaves of the same fine texture and silvery-grey hue as 

 the Weymouth Pine, from which, however, it differs in many 

 respects. It is a distinct Pine well worth growing, and no doubt 

 one of the very hardiest. 



Pinus Albeetiana. — Of this there is a promising tree only 

 planted in 1868, and now 12 feet high, resembling in some 

 degree the Hemlock Spruce, but of more vigorous growth. It is 

 likely to form an excellent addition to the pinetum, being evi- 

 dently very hardy, and starting at once into the tree form, not 

 lingering on as a mere bush. 



Picea Pinsapo, 44 feet high, densely branched to the ground, 

 forming as compact a cone as the best-formed Wellingtonia, the 

 closely-packed mass of twigs and foliage concealing the bole 

 nearly the whole way up. This tree was planted in 1844, and 

 during the last six or eight years has grown very fast. It has 

 only once had a few cones on if; — namely, in 1869, and these in 

 some degree resembled the cones of P. cephalonica. Most 

 persons who have seen this tree consider it to be the best of its 

 kind in England, and as Mr. Fleming does not mention it in his 

 list, I conclude that there is not a remarkably good specimen 

 at Dropmore. It is not the class of tree to please planters who 



