Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/244

 226 THE BUILDING NEWS. Marca 15, 1872. eS eee Intercommunication, —_<@—_—_— QUESTIONS. {2501.J—Iron Stains in Oak.—What is the most effectual way of removing iron stains from oak ?— F. H. [2502.)—S. Peter’s, Rome.—Will any reader inform me where I can procure, at moderate cost, a good detailed architectural history and description of S. Peter’s at Rome, from its commencement to its com- pletion ?— BRAMANTE. [2503.|—Magnetic North.—How many degrees does the magnetic north vary from the true north pole ? What is the supposed cause of the difference in variation? What is the best work to refer to on these subjects ?—A. BEAVER. [(2504.]—Heating Churches. — Would some of your readers kindly give me particulars of Porritt’s plan of heating, with particulars of cost, if possible, and also address of the party who supplies the appara- tus? I should be much obliged if some of your readers would give me their adyice upon any other cheap system for heating a village church accommodating about 300 people, with particulars of approximate cost. —ARCHITECT. 2505.)—Sections of Purlins.—Permit me to inquire which of three sections of purlins is considered best—9in. x 5in., llin. x 4in., or llin. x 3in.—in a queen post roof where the principals are 10ft. apart and purlins 6ft., with spruce rafters 3in. x 24in., and slate covering? Also, whether the modern practice by some builders of fixing purlins with their sides vertical, instead of at a perpendicular to the plane of the roof (as always taught and practised by our fore- fathers), is not a wrong practice ?—E. G. 2506.) —Wrought-Iron Girders.—Whenever a wood girder, joist, or beam, is required, it is a very easy matter to obtain the given size and weight it will support by looking into Tredgold’s, Newland’s, or Nicholson’s works, and I shall be glad to be informed by some kind subscriber if any work can be got giving rules for working out dimensions of wrought and cast- iron girders in a similar manner. Sketch A isa box WALL , re oO girder. The bearing is 20ft. ; the weight of wall, roof and part of floor it will have to support is about 14 tons. I shall feel grateful to be informed the substance iron for sides and top and bottom plates; also angle- iron, and the method of working it out. Sketch B represents two rolled iron girders put side by side. Supposing they were used instead of the box girder, how are their dimensions found, and would they not bestronger than that represented by section A ?—G, A. Saurn. [2507.|—Basalt.—Will any reader kindly tell me for what building purpose basalt is used, and state ap- pearance of same? In geological works, basalt is stated to be of yolcanic origin, and once molten lava.— Boake. Bs (2508.|—Sketching In and About London.— Will some one kindly tell me, through this column, whom to apply to for permission to sketch in West- minster Abbey? Also name a few notable ancient buildings in and about London, say within a radius of twenty miles, to visit for sketching purposes, — Rustic. [2509.]—Specification.—Can any fellow reader tell me how to get such information as will enable me to prepare a specification for a small building on ecclesiastical property, so as to meet the requirements of existing Acts of Parliament? I notice on p. x. of the Bur~pinG News for March 8 a work entitled “Dilapidations, Ecclesiastical and General, Adapted to the Act of 1871.” Will this work supply my want? —TEKTON. [2510.)—Pitch Pine.—Wood Staining.—Our highly-esteemed friend “ An Experienced Workman” remarks on p. 190, ** Pitch pine is admirably suited for all purposes when strength and durability are desired,” &e. Is this correct? I haye heard that the Govern- ment officials are now condemning pitch pine as unfit for building purposes, except where well exposed to the air; in fact, I am told that pitch pine has proved a complete failure where air is excluded. Can any friend authoritatively say which of the above remarks is correct? The articles by ** An Experienced Work- man” are so intensely interesting and useful, I take the liberty of asking if we may expect an index to the various processes treated on? I esteem the articles as most useful for reference; but, without an index, much time must be wasted in finding the particular article which may be wanted. I fully endorse his remarks at bottom of first column, p. 190. It is some years since I used any stain save those which he recommends, and I use them in the same way. Stains simply laid on with the brush hide the natural beauty of the wood, whilst rubbing takes off the superfluous stain; and those grains which are most porous, having imbibed the largest quantity of the stain, are brought out into high relief, thus making the beauty of the natural grain more visible, which is, in my opinion, the real object of staining. I have made very satisfactory work with Prussian blue mixed with burnt sienna, but the effect is rather uncertain, either atmospheric influences or some chemical difference in the Prussian blue itself causing it to haye a less pleasing effect at one time than at another. I consider water far preferable to oil for bringing out the grain ; but I generally use oil for out- door work. Perhaps some friend can tell me how to use the water stain for outdoor work without sacrificing durability —A CoNSTANT READER. REPL. [2476.]—Measures of Lime.—I find in Hopper’s “Practical Measurer” for 1853, a hundred of lime is 35 bushels. Gilbert R. Redgrave gets back to 1734, and finds 25 bushels = 1 ewt. ‘“ Birmingham” tells us lime is sold at per ton, no doubt meaning 112]h. = 1 cwt.—W. T. [(2476.]| Measures of Lime.—I had noted in my books the information given by ‘* Birmingham,” but Mr. Gilbert R. Redgrave (for whose elaborate and in- teresting reply allow me to thank him) has again put me in doubt. What I want to know is, according to London practice, how many bushels of stone lime (heaped or striked) go to a eubie yard, how many bushels of ground lime (heapedor striked) go to a cubic yard, and how many bushels of sand (heaped or striked) goto a cubic yard? I see that London price-books quote lime at per cubic yard. Mr. Redgrave quotes Batty Langley to the effect that a hundred of lime is 100 pecks,or 25 bushels ; but Mr, Tarn, in his ‘Students’ Guide,” says a hundred of lime is 35 bushels. Who is right ? and are the bushels heaped or striked?—A. H. [2482.]—Reservoir Construction.—Referring to my question in the BurLp1NG News of the 28rd ult., I hope some one will kindly give me information as to the above, especially as to the question of filtering. The ground falling away rapidly from the site of the reservoir, I had thought of constructing a small filtering chamberat a short distance below it,in brick and cement. Is it better to let the water filter up or down? Either could be done in thisease. Is there any special * tip” as to provision for emptying the reservoir when re- quired ?—DERMOD. (2490.] — The Pointed Style. — Brandon's “Analysis of Gothic Architecture ” is a first-rate work, which would probably meet ‘‘R. L. M.'s” needs. Theory requires that wherever pressure is concentrated on an arch, there should be a cusp to strengthen it for resistance. This may be shown by the catenary, which forms a cusp at any link where a weight is suspended, and Hooke’s discovery, “ut pendet continuum flexile, sic stabit contiguum rigidum inversum,” at once ap- plies this to the arch. For this reason, when an arch has to be loaded on the vertex, a pointed arch should be the form chosen; that so, the load may be on the cusp.—T. H. E. [2493.)—Firegrates and Flues.—Contracting a flue is when the chimney or arch-bar is fixed, the flue must be its intended size at bottom. It is done by short bars of iron, one end resting on arch oyer- opening, the other end resting on chimney-back. I have built the flues on this plan for eighteen years, and sayed the expense of chimney-pots. Iam always watchful, when the stoves are set, to have them set with brickwork, not the space at the back of stove filled up with dirt.—W. T. (2495.]—Liability of Gas Companies.—In reply to ‘L. J.,” although A.’s gas company have no Act of Parliament, yet if the undertaking be authorised by a provisional order, made under the Gas and Waterworks Facilities Act, 1870, then the recovery of gas rent due from A. may be enforced by cutting off the service pipe, and the expense so incurred may, to- gether with the sum due, be recovered from him by summons before a magistrate, and by a warrant of distress, under the Gasworks Clauses Act of last session, 34 & 35 Vict., 41.—N, [2495.]—Liability of Gas Companies.—The question as to liability of gas companies raised by this question, is very readily answered. Under the Gas- works Clauses Act, 1847 (10 Vict., c. 15), 8. 16, gas companies haye power, in case of any person supplied by them neglecting to pay the rent, to prevent the gas from entering the premises of such person, by cutting off the service pipe, or by such means as they shall think fit. If the company referred to is formed under the Gas and Water Facilities Act, 1870, that Act provides that the provisions of the Gasworks Clauses Act, 1847, shall be incorporated, save where expressly yaried or excepted by the provisional order under which the company is formed.—aA. §, N. (2498.| Gauging Sheet Lead.—An iron gauge can be made from the following:—For milled lead, the weight per foot, according to the several thick- nesses, is as follows:—One-sixteenth of an inch thick, 33lb.; one-twelfth, 51b.; one-tenth, 61b. ; one-eighth, TAlb. ; one-sixth, 101b.; one-fifth, 12lb.; One-quarter, 1431b. ; one-third, 19 {lb.; one-half, 29}1b. ; three-fourths, 4211b, : one inch, 591b.—W. T. [2498.] Gauging Sheet Lead.—Seme yearssince I invented a gauge for measuring the thickness and weight of metal and other plates, the principle of which is the progressive moyement of an accurately-cut screw. To this is affixed a circular index or micrometer-head (vide the catalogue of the Great Exhibition in 1861, class 10, No. 298). I have a very small gauge made expressly for architects, surveyors, &c., with two lines of numbers—one gives at sight the exact weight per foot super. of sheet lead up to Slb., and the other line of glass up to 320z. to the foot super. From the same gauge may also be ascertained the weight per foot super. of all other substances by the use of my sliding scale of equivalents. The outer circle of the dial is divided, so that each minor division represents loz, per foot super. of sheet iron, specific gravity 7°68, the pounds and quarters being marked off up to 201b, to the foot. The next circle is so divided that each minor division represents the 1000th part of an inch,the num~- bers 1 to 50 being 100ths of an inch, This line is sug- gested for adoption as a practicable application of deci- mals for an “imperial” gauge, in lieu of the arbitrary and conflicting measures now in use, few of which have any definite value with respect either to thickness or weight. The inner circle gives the Birmingham wire gauge. But as the various authorities differ as to the thickness they assign to almost every number, those there set out are the mean results of many trials with gauges issued by the manufacturers of these articles, and of references to the works “of those who have written on the subject.—E. L. HAYWARD, 79, Cornhill, E. C. (2499.]—Red Ants.—Place as near as possible to the tracks of the ants some ordinary jam pots, about half filled with brown sugar and water, mixed to the consistency of syrup, and do not remove themfor some days.— NODE. —_<._—__ PARLIAMENTARY NOTES. §. James’s PARK.—Mr. W. H. Smith on Thursday week asked whether it was the intention of the Government to proceed with a Bill, for which plans had been deposited, under which it was proposed to obtain powers to take a plot of ground in S. James's Park upwards of 350ft. in length, and from 50ft. to 70ft. in depth, for the erection of additional offices for the Admiralty, and,if the Bill was to be pro- ceeded with, when it would be introduced.—Mr. Ayrton replied that the Bill referred to was in course of preparation, and would, he hoped, be introduced before Easter, or at all events immediately after- wards. He could not, however, quite accept the assumption on which the question was based that it was intended to take special powers by Act of Parliament to build over this land. The land, of course, was part of the property of the Crown, and part therefore of the ordinary resources of the Crown for the purpose of carrying on the govern- ment of the country. It was quite available for the purpose of building offices if necessary. But the object of the Bill was more especially to obtain land which belonged to private persons. It was not in- tended to build over the whole of the land described in the deposited plans, but merely to build within those limits. IMPROVEMENT OF LABOURERS’ DWELLINGS IN TRELAND.—In answer to Mr. Downing, the Marquis of Hartington said he was unable to state the day when he would introduce his bill for the improve- ment of labourers’ dwellings in Ireland, but he hoped to be able to do so before Haster. MerropouirAN TRAMWAYS. — Earl Cowper moved on Monday in the House of Lords that the Earl of Airlie, Earl Beauchamp, the Earl of Long- ford, Viscourt Eversley, and Lord Clinton he appointed to join with the Select Committee of the House of Commons to inquire into the question of metropolitan tramways proposed to be sanctioned by Bills in the present session, and to report:—(1) Whether it was desirable or not that any fresh tramways should be laid within the metropolitan area; (2) what should be the limits of the metro- politan area in respect of tramways; (3) under what atithority the construction and working of metropolitan tramways, if any, should be placed; (4) along what lines of streets tramways should bo allowed to be constructed, and under what restric- tions. The motion, after a brief conversation, was agreed to. inate S