Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/290

 272 THE BUILDING NEWS. Aprit 5, 1872. English serpentine, will require to be altered | engravings, and the principle can be shown in some degree from the natural form. ‘The best kind of sponge is the strong leathery open sponge, and not the soft close sponge, so much prized for the use of ladies. The right sort of sponge will have the cells or openings some large and others small, but all of a tough leather-like texture. Some of these are exceedingly rotten, and break in working ; these are not worth the trouble of working. We purchase a large piece and while it is dry and stiff cut it into convenient sizes with a sharp knife ; these pieces should be cut with square sides and edges. We now soak them in water, so that we may see what form or shape they have. If the cells do not take the form we want, we cut out portions with a pair of scissors, making two cells into one, and breaking up any circles (for it is a fact that we very rarely, if ever, see a circle, a square, or a straight line in any kind of marble); and if there are any parts which are without openings or cells we burn holes in those parts with a red-hot wire or piece of iron; this will make the sponge hard and rough, but when it is dry it may be put straight by rubbing on a sheet of sandpaper. As a matter of course, we have a variety of these sponges, some fine and some coarse, and in doing some kinds of granite we use a needle and thread and cross some of the larger cells with the thread, which in carrying colour for graining produces a capital effect. We require also several small pieces of sponge to enable us to work into the angles, the mouldings, and interstices, where the larger sponges are useless. These sponges should be about three inches in thickness, so that we may hold them with the hand in working without danger of daubing ourselves, and in working the sponges they should always be wet before they are put into paint, and put into water when left for even an hour, and when done with they may be washed perfectly clean with soft soap and warm water. Sponges are expensive things, and require the greatest care to keep them in working order, and, as we shall show, are very useful for the purpose. (To be continued.) “> —_——_ PLUMBING.—VIL. (Continued from page 213.) N last article the style of covering flat on top of roof with zine was described. In this we shall speak of covering sides of roof with zinc. Before beginning to lay zine up the sides the gutters have first to be laid, and we may suppose the front one to be of the style shown in Fig. 8, p. 171, while the back gutter may be of the style shown by ‘‘S,” p- 95. These gutters may be either of lead or zinc ; but as for my part I prefer lead for the gutters we shall suppose lead to be used for the gutters here. The apron shown at Q, Fig. 8, p. 171, may be of zinc ; in fact, in towns it is a good thing to have this apron of zine, because when of lead it is often taken away, and it is better, therefore, to lock the door before the steed is stolen than after it has vanished. In order to stiffen it, the lower or outer edge of zine aprons, or flashings, has to be set in a little, as per Fig. 47. In setting up sheet zine to the sizes and shape necessary to make it fit its intended site, it is turned over the edge of an iron- faced bench, or if, as is often the case, the zine is set up at the job, then in many cases a long, stout, sharp-edged wooden plank is made to serve the purpose in lieu of the bench proper. In the sketch of gutter at Fig. 8, the wooden fillet or ‘doubling” for slates is shown at top edge of lead; such “doubling,” however, is dispensed with here, as in this ease we are not to have any slates. The style of roof is the common gable, or ‘ pent” roof, and, for illustration, I shall suppose it to be 10ft. long between the sques (the reason why I suppose the length to be only all the same with a length of 10ft. as with Fic.47 ~ Fia.48 | 1 wl one of 100ft.), the depth of roof from ridge to LOft. is in order to economise the space for | gutter channel being, we shall say, lift. Be- fore doing anything else to roof, the whole surface ought to be examined to see if there are any nails, &c., projecting above the sur- face, and if there be any such thing they must all be well punched down. The gutter being laid, and its top edge next slope of roof bent over about 2in., as per Fig. 48, the number and site of rolls must then be fixed. As the length between the sques is 10ft. and the 8ft. by 3ft. zine sheets are all to be cut up the middle longitudinally, it follows that there will be seven rolls, and also eight sheets therefore, be marked off in centre of roof, as per D, Fig. 49. The full breadth of our zine sheets, after being cut up, beingnow 1ft. 6in., it follows that as 1Jin. is to be allowed for upstands on each side of sheet there will only be a distance of 1ft. 3in. between the rolls, as also that the number of rolls re- quired will, as we have said aboye, be seven, as shown on Fig. 49. As the size of zinc roll-caps is in this case to be l4in., Fig. 50 shows full-sized section of wwood-roll suitable for same. (The outer circle, shown on Fig. 50, is full-sized section of zine roll-cap, and the dotted lines show zine sheets as turned up against wood-roll.) The wood- roll, Fig. 50, is about 1gin. broad by 1Zin. high over all. It is best to be made and put on in two pieces as described for 2in. rolls on page 212. (At page 212 it will be observed that whereas about middle of first column it says, ‘‘wooden rolls are to be nailed on, of which Fig 36 shows full-sized section suit- able for 2in. zine roll-eaps; this wood-roll is 1fin. broad, and about 28in. high over all,” the size shown by Fig. 36, instead of either measuring “lyin. broad, and about 23in, high,” or being ‘full-sized section suitable for 2in. zine roll-caps,” is only about half the proper size. This non-agreement of the engraving with the text is probably owing to not giving special instructions that Fig. 36 should appear of the exact or full size of my sketch. he proper size asintended isgiven at page 244.) We therefore nail on the long strip E, Fig. 50, first, in centre of roof, as at D, Fig. 49, and at the distance of 1ft. 3in. from each side of it nail on other two pieces, and lft. 3in. from them other two, and lft. 3in. from the latter other two: in all seven strips, as shown by Fig. 49. After these long wooden strips are nailed on (as they extend from gutter up to ridge, the length of each is about 15ft.) the zine has to be turned in at bottom lin., as per F, Fig 51, and also turned down at top 2in., as per G, Fig. 51. The sides of sheets have then to be set up 14in. on each side, as per Fig. 52. After this is done a small strip of zine about 6in. long by 3in. broad is firmly soldered on to under side of sheet at top, as at H, Fig. 51; it is to be put on in centre of width, and its purpose is to support sheet, and keep it from slipping down after sheet has been put into its place. When sheet is put into its place three or four nails are driven through upper half of H, thereby fixing H to boarding, and so suspending the sheet. The lower portion of sheet, turned in as per F, Fig. 51, it will be understood, laps on to top edge of gutter, which was turned down to suit it, as per I, Fig. 53. Besides zine latchet H, Fig. 51, two other zine ‘‘clips,” about 6in. long by 2in. broad, are put on for top of each sheet, one at each side of H. They are merely nailed to boarding and turned into top of sheet, as per K K, Fig. 54. The eight sheets on lower half of roof next gutter being thus laid—except the two outside sheets next sques J J, Fig. 49, which may be set up 2in. or 24in. on next sque—it is seen that they only go about half-way up the side of roof; consequently other eight sheets, each 18in. broad, have to be taken and their bottoms turned in as per F, Fig. 51, and their sides set up, as per Fig. 52, while their tops may stop off at ridge, as per L, Fig. 55. Or, for another style of finish, the tops of sheets may be set up against ridge. The latchets H, Fig. 51, are
 * in length of roof. The site for first roll may,