1843.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



27 



During the last three or four months, I have had frequent oppor- 

 tunities of witnessing the operation of several different kinds of appa- 

 ratus for consuming smoke, some of them patented and some not ; the 

 whole of which I found wanting some improvement to render them 

 capable cf accomplishing their intended purpose still more effectually. 

 This circumstance caused me to try a plan of my own, the success of 

 which has induced me to hand you the present communication. After 

 all the discussion and bother that has of late been driven up and down 

 the country concerning the consumption of smoke, "smoke burning" 

 is, nevertheless, in my humble opinion, as far as Englishmen have been 

 enabled to succeed in the science, attended with so little difficulty as 

 to be accomplished with very little trouble and expense. My furnace 

 was recently one of the ordinary description, though it is now entitled 

 to the name of a "smoke-burner," and the difference of the state in 

 which it now is, and that which it formerly was, is simply this. 



Cold air being admitted through a regulating door cr valve built in 

 the wall on one side of the ash pit, into a space or chamber formed 

 within the wall which supports the fire-bridge, ascends through a 

 narrow aperture extending across the top of the bridge, that is from 

 one side of the boiler to the other into the flue, where it mingles, with 

 the smoke, and thas renders combustion more complete. The air 

 thus admitted into the flue can have no good effect any longer than it 

 assists combustion ; for this reason, if the engine man be a little atten- 

 tive, he will generally find that the air valve may be shut in about 

 four minutes after each renewal of the fire. 



There are many "smoke burners" now in constant operation in 

 this neighbourhood, some few of them appear to answer tolerably 

 well, while others, of the very same plan, appear to have no effect 

 whatever. This circumstance renders it impossible for a stranger to 

 distinguish the chimneys which have "smoke burners " attached to 

 them, from those which have not. I do not mean to say the plan I 

 here describe is a perfect remedy for preventing the smoke of chim- 

 neys ; it is such as I am convinced will protect me against any inter- 

 ference of the Leeds improvement commissioners; it has a better 

 effect in accomplishing its object than a great majority of those in the 

 neighbourhood ; and it is inferior to none I have yet witnessed, except 

 in one point, and that is of all others the most important, viz. expence. 

 From your humble servant, 



.Near Leeds, JVoo. 29, 1842. Fleece. 



[We did not think it necessary to give the drawing forwarded by 

 our correspondent, as we consider that the description will be suffi- 

 ciently understood without it; this "smoke burner " is, we believe, 

 identically the same as one that was patented some years since, which 

 patent has expired. — Ed.] 



BLAST ENGINES. 



Sir — I shall feel obliged by an explanation from you or from some 

 of your correspondents in an early number of yoju- valuable Journal, 

 of the following irregularity of blast from a blast engine. 



The engine blows four furnaces, three on one side, and one on the 

 other side. There are two receivers, one exactly opposite to the 

 gable of the engine house, into which the air is first /creed, and another 

 situated nearly equidistant from the three furnaces on one side of the 

 engine. The blast to the three furnaces is taken from the bottom of 

 the receiver at the engine house, and to the other furnaces, within a 

 short space of the top, and about one foot above the orifice through 

 which the blast passes from the engine to the receiver. I applied a 

 mercurial gauge to various parts of the pipe leading to the single 

 furnace, and 1 found the pressure varying irregularly from a quarter 

 to three and a half pounds on the square inch ; whereas the pressure 

 on the pipes leading to the three furnaces kept uniformly three and a 

 half pounds. 



I am, Sir, 

 Your most obedient servant, 



Clyde Iron Works, Glasgon, William Ferrie. 



December 27, 1S42. 



ON THE STRENGTH OF BEAMS. 



Sir — The above sketch shows the situation of the supports, &c, of 

 a cast iron beam I lately had an occasion to make use of for carrying 

 a load of about seven tons at each end. The distance between the 

 supports s, 8, was six times as great as that between the centre of 

 each load, W, and the nearest support. 



Now, I should feel myself highly obliged if some of your scientific 



readers would be kind enough to furnish the Journal with a correct 

 method of shaping beams of this class; also the best formula for 

 computing their strength. To prove where a beam of this kind 

 would break, I took a parallel square bar of cist iron, divid 

 length, and placed it upon two supports, as seen in the sketch, then 



W 



W 



submitted it to a pressure, acting equally upon the points, W, W, till 

 it broke in the points c, c. Was I not to' infer from this circumstance, 

 that beams of the present kind rpquire to be made strongest between 

 the points of support ? Query— Would this inference be c „isist.>nt 

 with theory ? I don't remember seeing in any author on the subject, 

 any satisfactory information relating to this class of bearers ; still it is 

 a form which in general practice is often found very convenient : and 

 I have no doubt that if some of your able correspondents would give 

 the subject a thorough investigation, the result thereof would be 

 generally received as being of great practical importance. 



Leeds, Dec. 17, 1842. Concrete. 



OBSTRUCTIONS TO WINDOWS. 



Sir — I have repeatedly endeavoured to obtain definite information 

 on the subject of obstructions to windows (which have acquired a 

 right by being opened upon adjoining property the requisite length of 

 time) but having been unable to obtain any thing to be relied on, per- 

 haps you, or some of your numerous and well informed correspondents 

 can afford light on the following subjects. 



1. Suppose a window to be opened upon an adjoining property, and 

 (by neglect of the owner of such adjoining property; to acquire a right 

 to remain open. What space of ground is required to be left open 

 for its use, say in a direct line from its face, or the face of the wall in 

 which it is built or opened ? 



2. Does the opening such window (of course it being possessed of 

 the right as above) give any right to space on each side, or more 

 than its own width. 



3. Does it preclude the building of any structure beneath it, or as 

 high as its sill. 



These queries, you will perceive, are intended to cover all the 

 ground of right of occupancy inherent in [windows, which have been 

 allowed to remain open a length of time sufficient to give what is 

 termed a right of light. 



By replying to the above, or giving it a place in your valuable 

 journal, 



You will oblige, 



West Derby, Dec. 5, 1842. An Old Subscriber. 



[We rather suspect that our correspondent will find some difficulty 

 in obtaining a satisfactory answer to his queries, 1 and 2 ; we believe 

 that theie has not been any defined distance settled. At a trial, much 

 depends upon the hard swearing of witnesses on both sides, as to 

 whether a building erected near a window does obstruct the light and 

 free circulation of air. After hearing of evidence, it is left to the 

 Judge and Jury who may try the cause to determine the point. In 

 answer to the third query, there is no doubt that the owner of the soil 

 has a right to build beneath the window or as high as the sill ; if in 

 London, the roof must be 18 inches below or from the opening, to 

 conform to the building act. — Ed.] 



SMITH'S PATENT WIRE ROPE. 

 At the Society of Arts, on Wednesday, the 14th December, a 

 paper by Mr. A. Smith was read, " On the propertit* of Win , M applied 

 in the Manufacture of Rope for Mining and Railway I'm/ osa, Stan l- 

 ing Rigging, Lightning Conductor*, Cablet, .St." After some pre- 

 liminary remarks on the increment of strength, as compared with 

 diminution of bulk, resulting from the processes of drawing and 

 annealing the wire, Mr. Smith gave a table of the strenglh of single 

 wires of various gauges, the breaking weights ! avingbeeu obtained by 



experiment with the testing machine. This was followed by a table 



of tests of the comparative strengths of the Govern nl hempen-rope, 



and Mr. Smith's wire-rope, from experiments ordered by the Admi- 

 ralty in March, 1837. Another table gave the comparative size, with 

 the weight, and cost per fathom, of iron-wire rope, hempen-rope, 



