158 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Mat, 



inner side, so as to form altogether a series of eighteen liltle jets of flame, 

 sbc vertical ami twelve horizontal, all converging to a common centre — the 

 point, therefore, of the greatest heat. Knowing that a mixture of coal gas 

 and a proportion of the atmosphere hums with a pale blue flame, containing 

 no solid carbon, giving only a feeble light, hut possessing a vcrv' high tem- 

 perature, it occurred to Mr. Solly to employ this mixture instead of hydrogen 

 in the jets above described, by the injection of air into the coal gas pipe. To 

 the end of a common gas cock, comiccted with the street main, a piece of 

 copper pipe is attached, four inches long and a quarter of an inch in dia- 

 meter; outside this is another piece of capper tube, six inches longer, and 

 ■with a proportionahly larger diameter than the internal. The air which is 

 to mix with the coal gas is admitted into this longer external tube — the 

 quantity being regulated by cocks, the object being to eftect the most favour- 

 able mixture, as a diminution of pressure would be caused if the two currents 

 did not flow in the same direction — whilst by the present contrivance the 

 pressure is partially augmented. When the lamp is used, the crucible to be 

 heated is supported on the top of the horizontal circle of jets by a triangle of 

 platinum wire, so as to place it in the centre of the greatest heat ; it is thus 

 heated by eighteen little blowpipes, and becomes brightly ignited in a few 

 seconds, the heat increasing as the platinum becomes ignited ; the furnace is 

 rendered more complete by a thin cylinder of sheet-iron, three inches in dia- 

 meter and two high, which is placed above the horizontal circle, to prevent 

 the flames being blown about by draught of air, and a circular disc of the 

 same metal, having a hole in its centre of an inch across, to place at the top 

 of the cylinder — this causing the heated air to pass round the upper edges, 

 and over the lid of the crucible, and thus bringing the whole to the same 

 temperature. The heal is rather above the melting point of silver, and is, 

 of course, equal to the fusion of mixtures of silicates witli carbonate of soda 

 — 300 grs. or 400 grs. of a mixture of carbonate of soda and a sihcious com- 

 pound being perfectly fused in about eight minutes. The inventor considers 

 this lamp superior to any other, whether as a simple and economical method 

 of decomposing earthy silicates, or for other innumerable purposes where a 

 bright red or yellow heat is required, and where an ordinary furnace is in- 

 applicable ; and, as it is an efficacious mode of heating a platinum crucible 

 to bright redness, without exposing it to the contact of solid fuel, the at- 

 tempt appears perfectly successful. — Mining Journal. 



WILLIAMS AND SOWERBY'S SHOW ROOM, &c. 



Sir, — Accept my thanks, and let the architect do so also, for giving 

 us the plan of Messrs. Williams and Sowerby's new room. The 

 having previously seen the apartment itself did not render the plan of 

 it less welcome io me ; on the contrary I was all the more desirous of 

 having a drawing explanatory of various particulars that I could not 

 trust to my memory for. The idea there produced is not only highly 

 ingenious and novel, but valuable for its suggestiveness. Unborrowed 

 and fresh, it is also stimulative, and calculated to excite invention, 

 whereas the overweening and too exclusive study of what are usually 

 reeeived as correct and standard models for our direction, is, in my 

 opinion at least, apt to keep the inventive faculty dormant, or to send 

 it fast asleep, and to deter from the exercise of fancy by the dread of 

 incurring from the dull the reproach of henig/ana/ul. 



We need now and then to have a few fresh ideas administered to 

 us ; even should tliev be rather rough ones they are still of worth, because 

 they may all the more easily be improved upon, and be more fully deve- 

 loped and wrought out. There have been, I am inclined to believe, a 

 great number of contrivances more or less ingenious, either arising out 

 of sheer necessity, or else originating in mere " whims" and " fancies," 

 ■which, instead of being preserved and turned to account in similar 

 cases, are forgotten and lost because they have never been recorded in 

 books. Multitudinous as are the publications of one sort or otker 

 ■upon architecture and architectural decoration which issue from the 

 press. The Book of Contrivances remains to be written ; before 

 which could be done there would be the task of hunting out materials, 

 and they are of a kind not to be compiled from books, since very little 

 for the purpose is so to be gleaned. If, indeed, every one who 

 could do so would contribute his mite — the contrivances that have 

 come under his own observation, or such as have occurred to, if not 

 been executed by himself, a highly useful and instructive work might 

 he produced. 



At present there is not a single work, either English or foreign, as 

 far as I can find out, which treats systematically of interior decoration 

 and effect, and goes into the rationale of those subjects. Of mere pat- 

 tern-books of ornaments and individual architectural members and 

 details in various styles there is no lack, and we occasionally meet 

 with compositions for the entire embellishment of a room, but we also 

 very much want a full treatise on the subject, wherein might be em- 

 bodied all the desultory and scattered remarks that might be brought 

 to bear upon it. 



One thing relative to which I can find nothing is the mode of pro- 

 ducing various striking effects by the arrangement of mirrors and com* 



parUnents of looking glass. As an idea of the kind, I may refer to an 

 instance where what was originally a mere lobby, about twelve feet 

 by six, between a drawing-room and conservatory, was transformed in 

 appearance into an elegant vestibule twenty-four feet in length by 

 twelve in breadth, with an arched ceiling having twelve compartments, 

 six on each side, filled in with stained glass, although there were in 

 reality only three. Here was an effect which a man might study 

 Vitru'vius, Alberti, Palladio, Chambers, and all the writers of that 

 class, without ever even so much as dreaming of: how was it con- 

 trived ? It was merely — but no, I will not at present give the solution 

 of the problem, because your readers will no doubt be able to find it 

 out themselves, now that they are thus put upon the scent of it. 



I remain, &c., 



L. 



ARCHITECTURE AT MANCHESTER. 

 .Sir,— It is not a little annoying to find those who have apparently 

 both the means and disposition to afford information, perform their 

 volunteer office listlessly and only by halves. Without imposing any 

 additional trouble upon himself, your correspondent "C. E." might 

 have been more communicative when he had his pen in his hand. 

 He speaks of the Railway Station in Store Street, Manchester, as 

 being " a work of very considerable architectural merit," yet without a 

 single syllable further to afford us the slightest idea of what the design 

 is, or even in what style it is. Accordingly, he seems to be of opinion 

 that the degree of merit he would fain impute to it is, after all, not 

 such as to entitle it to more than bare mention, and its architect not 

 even to so much. It is precisely the same with respect to the "Pa- 

 latine Hotel ;" that also is praiseworthy for its " external design," 

 although erected by some nobody without even a name — strange that 

 there should be such a very general and unaccountable reluct- 

 ance to let the public know the designers of buildings. Scarcely- 

 more satisfactory is what is said of Worsley Hall, there being not a 

 word to convey any notion of its general form and size, or to point out 

 to what building in the same style it most approximates in character. 

 Does it, for instance, bear any resemblance to Burleigh, or to Hatfield, 

 or to Holland House ; or is it unlike them all, and equally dis- 

 similar from all other examples of the kind ? The writer might 

 also have helped us to some notion of its size. Since he has not done 

 so, my hope now is that he will take up his pen again, and furnish the 

 information here asked for, as he certainly can do if he please, after 

 having actually seen the buildings in question. Nor ought he to con- 

 sider it too much trouble to reply to an inquiry which he might have 

 anticipated by being a little more explicit. 



I remain, &c., 



D. T. 



VARIATION OF THE MAGNETIC NEEDLE. 



Sir, — I beg to draw your attention to the omission from your 

 Journal, for many months past, of the Variation of the Magnetic 

 Needle. To myself, and I have no doubt to others of your numerous 

 readers, regular information of the perodical variation is very interest- 

 ing, and, what is more important, of great utility. I will instance to 

 you the regular progress, for a series of twenty years, of mining ope- 

 rations in a certain seam of coal, of which operations a plan has been 

 kept ; the excavations being laid down upon it from time to time as 

 the workings extended from the various shafts. Now the usual mode 

 of keeping such a plan, is to procure in the first instance a plan of the 

 surface, with the magnetic meridian of the time being accurately laid 

 down upon it. The subterranean workings are afterwards surveyed 

 from time to time, their bearings ascertained by the magnetic needle, 

 and, with their lengths, laid down upon the plan. It is obvious, that 

 unless the alteration of variation be -ascertained by the surveyor, and 

 allowed for in his subterranean survey, a discrepancy will gradually be 

 generated between this and the surface plan, and between that of any 

 particular year and those of the years preceding it. 



On reference to Brewster's Treatise on Magnetism, I find that in 

 the year 1S23 the magnetic variation was 24° 9' 40". Now the last 

 account I can find in your excellent work is of the variation during the 

 months of January, February, March, and April, 1843, the average 

 being 23° S' 23", and the difference being \° 1' 17" between the variation 

 of 1843 and that of 1823. This variation would cause in a survey ex- 

 tending a mile in any given direction a discrepancy of 1*40 statute 

 chains between such survey and the (surface plan, and between such 



