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
