Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/331

 Aprit 19, 1872. THE BUILDING NEWS. 313 down inside, and so making those unsightly dirty marks often seen where the lead or zinc is improperly put on. The lower por- tion of glass ought not to rest closely on lead unless a channel or channels are cut out of wood underneath, into which lead has been dressed, so as to allow water to get ‘freely away. Fig. 87 shows section of lead going up under glass, and Fig. 88 is sketch showing how channel for water may be left in centre of each pane, the dotted line being top of putty, din. in thickness, which both keeps glass off lead and also prevents wind in an exposed situation getting in under pane, and perhaps either blowing it off or breaking it. Or, again, if joiner were cutting that much out of his wood at W, Fig. 88, the same purpose might be served without the putty, or some other plan might be adopted to suit the circumstances andthe form of window. Another roof window is the cupola of various shapes—round, square, and oblong. In many cases these cupola windows are brought and put on after the plumber has finished. Fig. 89 shows section of one side before window is puton, and Fig. 90 after window is on. X, Fig. 89, is the lead or zine gutter ; Y is lead apron overlapping upstand of gutter as shown, bending horizontally across block or ‘under-frame, upon which window-frame is to rest, and then up to Z as shown. The upstand at A, Fig. 89, is small lead pipes (say) 3in. high and the same in diameter, which are soldered to lead apron, and down through centre of which the screws to fasten down window-frame are put, as per Fig. 90. In putting lead aprons round circular windows the lead has to be dressed to fit circle ; one plan is to roll up the piece of lead apron and dress in the top side of it as if contracting a lead pipe ; when thishas beendone to one end of piece, unroll it, and then roll it up again, keeping the already contracted end inside, and so make both ends alike, and in this manner make piece of lead fit the circle. The “storm” or projecting window B, Fig. 91, is another roof window with a sque and flank going up each side and a ridge along top, there being also a triangular apren or flashing on each side, as shown at C, Fig. 91. The sketch supposes zine flashings and ridge, and lead sques and flanks, the rest of roof being slated. In some cases, however, when the sides, C, are pretty large, they are slated. Fig. 92, again, is quite the opposite to Fig. 91, his being as far recessed as the other is pro- jected. Fig. 93 shows how gutter and flash- ing are put in along top and down both sides. The flat before window is coyered with zinc, the two triangular sides and rest of roof being slated. Lead for domes is put on in something the same manner as described for flat at page 199—at least, so far as rolls are concerned ; but in cutting out lead to fit its site great care must be taken to cut it out properly, or it may be cut too narrow; it will not do to cut it out as per Fig. 94, for that would make it useless for the purpose, being much too narrow in middle ; it must be cut out in form of Fig. 95, and the swell made to correspond with circle of dome, and in cutting out the lead allowance must also be made, of course, for rolls. Since last article was published, I have received from Messrs. Braby and Co.— through the kind courtesy of their manager, Mr. Moore—a model of their late improve- ment in zine roll-caps. This improvement, as shown in Fig. 96, consists in bending up and working round end of roll-cap next ridge without soldering it, as at D, and also in bending down end of roll-cap next gutter or drip without any soldering, as at KH, the bending down at E being done by “ dog-ear- ing” (see pp. 170-171, March 1), the corners inwardly, as shown by dotted lines at E. Their system of embossing the zine up- wardly at hole for screw as at F, Fig. 96, is also good; it corresponds with that shown at Fig. 7, p. 171, for lead apron. In using vine care must be taken not to allow it to come into contact with lime, for lime eats it. Fisg30 ANU / I tf IHS Mh talon ft fe / /. alli NAGEL 7 am i i —— an ae INCA i VTEC a AA | ASA HAR TYAN =U Tin At p. 274, April 5, I gave a table of the weights of sheet zinc ; in this case I shall give table of its approximate thickness :— Sheet-zine Birmingham Thickness in gauge. wire-gauge. decimals of Parts of inch, No. No. an inch. Sinai se aeons 015 = 1-67th OUT ase ee ZO eee es 018 = 1-d56th NOME ase DOE cehsts 0208 = 1-48th Ula ewses 29) Wees ee 025 = 1-40th Lene Dak deta 028 — 1-35th Bhiecesce ZR 032 — 1-3i'st MA Fe ces OMe fees 035 © = 1=28th Dae Shi eases 040 _ 1-25th TWO” Ssnode LOB ies cas 043 — 1-23rd Ge ects WSN esses ‘050 = 1-20th The exact decimals of an inch of the Bir- mingham wire-gauge I understand to be :— 26° 25 24 23’ 22) 21° 20 19) 7 18 018 -020 -022 :025 -028 :032 -035 -042 -049 A square foot of zine lin. thick weighs 600oz. or 3741b ; from aboye table we therefore see that No. 11 zine, e.g., is ‘025 or 1-40th of an inch thick, and that it would therefore re- quire 40 thicknesses of it to make up one inch. Then, if we turn to page 274, we find from the table there that No. 11 zine weighs 150z. to the square foot. Now, if we multiply 15oz. by 40, we get 600o0z., or 374lb. Or, again, taking No. 15, we see it is -040, or 1-25th thick; then, as per page 274, multiply the 240z. there given for No. 15, by 25, and we also get 6000z., which shows that it re- quires 25 thicknesses of No. 15 sheet zine to make up lin. in thickness. Then to get the weight of one cubic inch of zine, divide the 6000z., above given, by 144, and we get 4§oz. as the weight of a cubic inch of zinc. I may add here the two following rules from Messrs. Braby and Co.’s circular, which may be use- ful :— Rule to obtain contents of any square or oblong tank.—Multiply the length by the breadth, and the product by the depth; the result multiplied by 6} gives contents in gallons. Rule to obtain contents of round cisterns or tanks.—Multiply the diameter by itself in inches, and the product by -7854, then mul- tiply this product by the depth in inches, and you get the number of cubic inches. There are 277} cubic inches in a gallon of water ; e.g. a cistern 18in. diameter, and 3ft. high, would contain, approximately, 33 gallons, 277; being used as the divisor. A cubic foot of lead weighs 11,3520z., or 70931b. (water at 40° Fahr. weighing 1,000oz.) A square foot of lead, lin. thick, will, there- fore, weigh 591b; but suppose we call it 601b., we get the following thicknesses for the following weights of sheet lead :— Weight per sq. ft, in Ib. Parts of inch. LOE es aaa coe -.. 1-6th Sees ces es ... 2-L5ths Why ie date ee ED Oj tens aor eer ... 1-10th Diaees ae ace .. L-12th 4 hess ane cee seen el—15th: Siyivae ets ie ... 1-20th A cubic inch of lead weighs fully 640z., and as we said above that a square foot, lin. thick, weighed 591b., or 9440z., a circular slab 1ft. in diameter and lin. thick would weigh fully 7350z., and a lead circle piece, lin. diameter and lin. high, weighs five ounces and one-tenth. To get this latter, multiply 6}0z. by -7854; and to get the 7350z. for circular slab 12in. in diameter, square the diameter, and multiply by -7854, which gives number of cubic inches, then multiply by 6} for number of ounces. Again, if circular were cylinder 10in. high, then 12 x 12 X ‘7854 x 10 X 64 = 7,351oz., or, more correctly, 12 ~ 12 x ‘7854 x 10 x 6569 = 74300z. To get area of a right-angled triangle, multiply the base by half the height; thus, base 4ft., per- pendicular 4ft., gives 4 x 2 = 8ft., which Sft., it will be observed, is exactly half the area of a square 4ft. in the side. To