Scientific American Supplement, No. 401, September 8, 1883

V >> Various >> Scientific American Supplement, No. 401, September 8, 1883

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[Illustration: FIG 1. IMPROVED SPRING TRACTION ENGINE.]

[Illustration: FIG. 2]

* * * * *

TABLE SHOWING THE RELATIVE DIMENSIONS, LENGTHS, RESISTANCES, AND WEIGHTS
OF PURE COPPER WIRE.

DIAMETER | AREA
|
B.W.G Inch. Milli- | Circu- Square Square
No. metres | lar inches. Milli-
| Mils. metres.
|
0000 .454 11.5313 | 206116 .161883 10.4435
000 .425 10.795 | 180625 .141862 9.152
00 .38 9.6518 | 144400 .113411 7.3165
0 .34 8.6358 | 115600 .0907922 5.8573
1 .3 7.620 | 90000 .070686 4.5602
2 .284 7.2134 | 80656 .0633472 4.0867
3 .259 6.5784 | 67081 .0526854 3.3989
4 .238 6.0451 | 56644 .0444881 2.8701
5 .22 5.5879 | 48400 .0380133 2.4523
6 .203 5.1561 | 41209 .0323655 2.088
7 .18 4.5719 | 32400 .0254469 1.6417
8 .165 4.1909 | 27225 .0213825 1.3794
9 .148 3.7591 | 21904 .0172034 1.1098
10 .134 3.4035 | 17956 .0141026 .9096
11 .12 3.0479 | 14400 .0113097 .7296
12 .109 2.7701 | 11881 .00933133 .60199
13 .095 2.4129 | 9025 .0070882 .4573
14 .083 2.1082 | 6889 .00541062 .34906
15 .072 1.8288 | 5184 .00407151 .2486
16 .065 1.6510 | 4225 .00331831 .21407
17 .058 1.4732 | 3364 .0026421 .17045
18 .049 1.2446 | 2401 .00188574 .12165
19 .042 1.0668 | 1764 .00138544 .0894
20 .035 0.8890 | 1225 .000962115 .06207
21 .032 0.8128 | 1024 .00080425 .05188
22 .028 0.7112 | 784 .000615753 .03972
23 .025 0.635 | 625 .00049087 .03167
24 .022 0.5588 | 484 .000380133 .02452
25 .02 0.508 | 400 .00031416 .02027

26 .018 0.4571 | 324 .000254469 .01642
27 .016 0.4064 | 256 .000201062 .01297
28 .014 0.3556 | 196 .000153938 .00993
29 .013 0.3302 | 169 .000132732 .00856
30 .012 0.3048 | 144 .000113097 .007296

LENGTH AND WEIGHT

B.W.G Pounds Pounds Pounds Pounds Feet Yards 1.000 feet Miles
No. per per per 1.000 per per lb. per lb. per lb. per lb.
foot. Yard ft. mile.

0000 .623924 1.871772 623.924 3294.32 1.60276 .534253 .00160276 .00303553
000 .54676 1.64028 546.76 2886.89 1.82895 .60965 .00182895 .0034639
00 .437105 1.311315 437.105 2307.92 2.28777 .76259 .00228777 .004333
0 .349928 1.049784 349.928 1847.62 2.85773 .9525766 .00285773 .0054124
1 .272435 .817305 272.435 1438.43 3.6706 1.22353 .0036706 .0069519
2 .244151 .732453 244.151 1289.11 4.0958 1.365266 .0040958 .0077573
3 .203058 .609174 203.058 1072.15 4.9247 1.641566 .0049247 .009327
4 .171463 .514395 171.465 905.333 5.8321 1.944033 .0058321 .0110457
5 .14651 .43953 146.510 773.56 6.8255 2.275166 .0068255 .012927
6 .124742 .374226 124.742 658.638 8.0165 2.672166 .0080165 .015183
7 .098076 .294228 98.076 517.844 10.1962 3.39873 .0101962 .019311
8 .082411 .247233 82.411 435.135 12.1345 4.04483 .0121345 .022981
9 .066305 .198915 66.305 350.089 15.0818 5.027266 .0150818 .028564
10 .054354 .163062 54.354 286.99 18.398 6.13266 .018398 .034845
11 .04359 .13077 43.590 230.152 22.9413 7.6471 .0229413 .04345
12 .035964 .107892 35.964 189.893 27.805 9.2683 .027805 .05266
13 .027319 .081957 27.319 144.245 36.6046 12.20153 .0366046 .069326
14 .020853 .062559 20.853 110.1088 47.954 15.98466 .047954 .09082
15 .015692 .047076 15.692 82.855 63.7267 21.24223 .0637261 .12069
16 .012789 .038367 12.789 67.5276 78.1902 26.0634 .0781902 .14809
17 .0101828 .0305484 10.1828 53.7665 98.202 32.734 .098203 .18589
18 .00726795 .02180388 7.26796 38.3748 137.590 45.8633 .137590 .260587
19 .00533972 .01601916 5.33972 28.1937 187.276 62.4253 .187276 .35469
20 .00370815 .01112445 3.70815 19.579 269.676 89.892 .2696676 .51075
21 .00309972 .00929910 3.09972 16.3665 322.610 107.5366 .322610 .61100
22 .00237312 .00711936 2.37312 12.5301 421.384 140.4613 .421334 .798078
23 .0018910 .0056757 1.8919 9.9892 528.570 176.190 .528570 .100108
24 .0014650 .0043950 1.4650 7.7357 682.55 227.5166 .68255 .129271
25 .00121082 .00363246 1.21082 6.39315 825.880 275.2943 .825883 .156417
26 .00098077 .00294231 .98077 5.17844 1019.61 339.870 1.01961 .193108
27 .00077492 .00232476 .77492 4.0916 1290.44 430.1466 1.29044 .24440
28 .0005933 .0017799 .5933 3.13264 1685.48 561.8266 1.68548 .31922
29 .000511571 .001534713 .511571 2.7011 1954.76 651.5866 1.95476 .370220
30 .0004359 .0013077 .4359 2.30152 2294.13 764.710 2.29413 .434496

LENGTH AND RESISTANCE

B.W.G Feet Yards 1.000 feet Miles Ohms Ohms Ohms Ohms
No. per Ohm. per Ohm. per Ohm. per Ohm. per foot. per yard. per 1.000 per mile.
foot.

0000 19966.5 6655.5 19.9665 3.7815 .000050684 .00156252 .050084 .264443
000 17497.15 5832.3833 17.49715 3.31385 .0000571522 .0001714566 .0571522 .301763
00 13988.64 4662.68 13.98804 2.64925 .000071489 .000214467 .071489 .377465
0 11198.17 3732.7333 11.19817 2.12086 .0000893002 .0002679006 .0893002 .471505
1 8718.30 2906.10 8.71830 1.6512 .00011470 .0003441 .114701 .60562
2 7813.50 2604.50 7.81350 1.47973 .00012799 .00038397 .12799 .67580
3 6498.14 2166.0466 6.49814 1.23071 .00015389 .00046167 .15389 .81254
4 5487.107 1829.0357 5.487107 1.03923 .000182245 .000546735 .182245 .962256
5 4688.51 1562.8366 4.68851 .887975 .000213287 .000639861 .213287 1.12616
6 3991.91 1330.6366 3.99191 .756045 .000250506 .000751518 .250506 1.32267
7 3138.59 1046.1966 3.13859 .59443 .000318614 .000955842 .318614 1.68228
8 2637.29 879.0966 2.63729 .499486 .000379177 .001137531 .379177 2.00206
9 2121.84 707.280 2.12184 .401864 .000471289 .001413867 .471289 2.488405
10 1739.40 579.80 1.73940 .329432 .000574911 .001724733 .574911 3.03553
11 1394.93 464.9766 1.39493 .264191 .000716882 .002150646 .716882 3.78514
12 1150.91 383.6366 1.15091 .217976 .000868875 .002606625 .868875 4.58766
13 874.252 291.4173 .874252 .165578 .00114383 .00343149 1.14383 6.03945
14 667.338 222.446 .667338 .12639 .00149849 .00449547 1.49849 7.91203
15 502.175 167.39166 .502175 .095109 .00199134 .00597402 1.99134 10.5142
16 409.276 136.42533 .409276 .077514 .00244334 .00733002 2.44334 12.9008
17 325.871 108.62366 .325871 .061718 .0030687 .0092061 3.0687 16.20274
18 232.585 77.52833 .232585 .04405 .0042995 .0128985 4.2995 22.7014
19 170.879 56.95966 .170879 .032363 .0058521 .0175563 5.8521 30.8991
20 149.3915 49.797166 .1493915 .022475 .00842703 .02528109 8.42703 44.4947
21 99.195 33.065 .099195 .018787 .01008110 .03024348 10.08116 53.2285
22 75.9461 25.315366 .0759461 .014384 .0131672 .0395016 13.1672 69.5230
23 60.54377 20.181256 .06054377 .011467 .0165170 .0495510 16.5170 87.2096
24 46.8851 15.628356 .0468851 .0088798 .02132874 .06398622 21.32874 112.616
25 38.748 12.916 .038748 .0073386 .025808 .077424 25.808 136.265
26 31.3859 10.461966 .0313859 .0059443 .03186144 .09558432 31.86144 168.229
27 24.79873 8.266243 .02479873 .0046967 .0403246 .1209738 40.3246 212.914
28 18.98653 6.328843 .01898653 .0035959 .05266892 .15800676 52.66892 278.092
29 16.3710 5.4570 .0163710 .0031006 .0610834 .1832502 61.0834 322.521
30 13.9493 4.649766 .0139493 .0026419 .07168825 .21506475 71.68825 378.514

RESISTANCE & WEIGHT

B.W.G Ohms Lbs.
No. per lb. per Ohm.

0000 .000080272 12457.5
000 .000104529 9566.7
00 .000163553 6114.24
0 .000255196 3918.58
1 .00042102 2375.18
2 .00052422 1907.59
3 .00075786 1319.50
4 .0010629 940.844
5 .0014558 686.911
6 .0020082 497.96
7 .00324863 307.822
8 .00460101 217.343
9 .00710791 140.689
10 .0105772 94.543
11 .0164462 60.842
12 .0241593 41.392
13 .0418692 23.8839
14 .0718583 13.9163
15 .126788 7.8872
16 .191045 5.2344
17 .301355 3.31835
18 .59157 1.6904
19 1.09596 .912445
20 2.27254 .44003
21 3.25229 .30748
22 5.54843 .18023
23 8.73035 .11454
24 14.5579 .068691
25 21.3142 .046917
26 32.4863 .030782
27 52.0367 .019217
28 88.7724 .011265
29 119.404 .008375
30 164.4762 .0060804

PURE COPPER weighs 555 lbs. per cubic foot. The Resistance of 1 mil.
foot at 60 deg. Fahr. is, according to Dr. Matthiessen, 10.32311 ohms. Upon
these data the above Table has been calculated.

The _Resistance_ of Copper varies with the temperature about 0.38 per
cent. per degree Centigrade, or 0.21 per cent. per degree Fahrenheit.

STRANDED WIRES.--With a conductor of a definite lenght, made of
_Stranded_ Wires, the total _weight_ is _greater_, and the _Resistance
less_ than is a similar length of Conductor with Wires _not_ Stranded.

To convert--Inches to Millimetres multiply by 25.3994
Feet to Metres " .3048
Yards to Metres " .9144
Miles to Kilometres " .6214
Pounds to Kilogrammes " .45359

PEPARED BY WALTER T. GLOVER & CO., ELECTRICAL WIRE AND CABLE MAKERS, 25,
BOOTH STREET MANCHESTER.

* * * * *

IRON FRAME GANG MILLS.

The gang mill is regarded as possessing material advantages in the rapid
and economical manufacture of lumber. Among the recent improvements
tending to perfect such mills, those which are shown in the iron frame
stock gang, manufactured by Wickes Bros., East Saginaw, Mich., are
eminently valuable. Our large engraving represents one of these mills,
constructed to be driven by belt, friction, or direct engine, as may be
desired. The important requisite in this class of mills is such design
and proportion of parts as will insure durability and continued movement
at the highest speed, safely increasing the quantity and improving the
quality of work done at a lesser feed, and admitting the use of thinner
saws than is practical in the slower moving sash. These are among the
advantages gained in the iron frame machine, overcoming the necessity
of an expensive mill frame, saving time and expense in setting up, and
avoiding the liability of decay or change of position.

[Illustration: IMPROVED IRON FRAME GANG SAW MILL.]

Many improvements have been made in the mechanism of oscillation, and
from these the builders of this mill have adopted what is known as the
Wilkin movement, which oscillates the top and bottom slides. The top
slides are pivoted at the top end, and the bottom ones from the bottom
end, both being operated by one rock shaft from the center. This
movement when properly adjusted gives an easy clearance and the easiest
cut yet obtained. It adds no extra weight to the sash, and avoids the
cumbrous rock shaft and its attendant joints, usually weighing from
three hundred to five hundred pounds, which have been found so
objectionable in many other movements. The feed is continuous, and is
made variable from 1/4 to 11/4 inch to each stroke, controllable by the
sawyer. Power is applied to the press rolls in the double screw form
with pivot point, also operated by the same hand. A special feature of
this machine is the spreading of the lower frame so that its base rests
upon an independent portion of the foundation from the main pillow block
or crank shaft. The solidity of the whole structure is thus increased,
both by the increased width at the base and the prevention of connecting
vibrations, which necessarily communicate when resting upon the same
part, as in other forms of such machines heretofore in use.

The mill shown in the perspective view is one of twenty-six saws 41/2 feet
long, sash 38 inches wide in the clear, and stroke 20 inches, capable
of making 230 strokes per minute. The crank shaft is nine inches in
diameter, of the best forged iron. The main pillow block has a base
61/2 feet long by 21 inches bearing, weighing 2,800 pounds. The cap
is secured by two forged bolts 31/2 inches in diameter, and by this
arrangement no unequal strain upon the cap is possible. A disk crank is
used with suitable counterbalance, expressly adapted to the weight and
speed of sash; a hammered steel wrist pin five inches in diameter, and a
forged pitman of the most approved pattern, with best composition boxes.
The iron drive pulley is 4 to 41/2 feet in diameter and 24 inches face;
the fly-wheel six feet in diameter, and weighing 4,700 pounds, turned
off at rim. When a wider and heavier sash is required, a proportionate
increase is made in all these parts.

In the construction of the sash the stiles are made of steel; the lower
girt and upper heads are made in one solid piece, without rivets, giving
the greatest strength possible, with the least weight. The outfit also
includes eight iron rollers for the floor, 81/2 inches in diameter, with
iron stands, and geared as live rolls when desired, a full set of
Lippencott's steel saw hangings, and gauges for one-inch lumber. The
weight of the machine here shown is 181/2 tons. They are, however, built
in larger or smaller sizes, adapted to any locality, quality or quantity
of work desired.

* * * * *

It is said that the St. Gothard Tunnel is diverting the bulk of the
Italian trade into the hands of the Belgians, Germans, and Hollanders
with startling rapidity. Without breaking bulk, early fruits are taken
from all parts of Italy to Ostend, Antwerp, and Rotterdam, whence they
are carried by fast steamers to London and other English ports. But, on
the other hand, Germany is sending into Italy large quantities of coal,
iron, machinery, copper, and other articles of which the latter received
nothing before. In two months alone, the Italians imported 1,446 tons of
paper.

* * * * *

THE HEAT REGENERATIVE SYSTEM OF FIRING GAS RETORTS.

The system of heat regeneration in the firing of gas retorts, in
accordance with the principle which Dr. C.W. Siemens has worked out in
such a variety of ways in the industrial arts, has lately been applied
with very marked success at the Dalmarnock Station of the Glasgow
Corporation Gas Works. Notwithstanding the fact that a period of about
twenty years has elapsed since Dr. Siemens successfully adapted his
system to the firing of retorts at the Paris Gas Works, it seems to have
made but little progress up to the present time; for what reasons it is
perhaps difficult to explain. It is certain, however, that so-called
regenerator furnaces of various forms have, from time to time, been
brought into use at gas works for the purpose in question both on the
Continent and in this country; and in recent years the subject has
received much attention from gas engineers, the general opinion
eventually being that the adoption of such a system of working would be
certain to result in so great an amount of economy as to put gas as an
illuminating agent on a more secure footing to compete successfully with
its modern and somewhat aggressive rival, the electric light. Of course,
it is now admitted that the mode of adapting the heat regenerative
principle at the Paris Gas Works was attended with a degree of
complexity in the structural arrangements that was so great and so
expensive as to place it practically beyond the reach of gas companies
and gas corporations generally, when the expense as well as the
scientific beauty and practical efficiency of the new mode of applying
and utilizing heat had to be considered. Fortunately, however, Dr.
Siemens was enabled two or three years ago to demonstrate that there was
no such thing as "finality" in that department of invention which he had
made almost exclusively his own. About the time mentioned he placed
his most advanced views on gas producers and on the regeneration and
utilization of heat before the world, and within that period a most
decided step in advance has been made, the structural arrangements
now required for gas producers and regenerator furnaces having been
immensely simplified and cheapened, while their practical utility has in
no way been interfered with.

Scarcely had Dr. Siemens announced his new form of gas producer and
regenerator than communication was opened with him by Mr. W. Foulis, the
general manager to the Glasgow Corporation Gas Trust, with the view of
entering into arrangements for its adoption on an experimental scale
at one of the stations under his charge. Encouraged by the hearty
co-operation of the gas committee, two or three of whose members were
well known engineers, Mr. Foulis very soon came to an understanding with
Dr. Siemens to have the regenerative system put to a thorough test at
the Dalmarnock Gas Works, situated in the extreme east end of the city,
and the largest establishment of the kind in Scotland, the total number
of retorts erected being about 750. The system in its most recent shape
was applied to four ovens, each of which had seven retorts, but which
number has since been increased to eight, owing to the space occupied
by the furnace in the ordinary settings being rendered available for
an additional retort in the new or "Siemens" setting. For each oven or
chamber of eight retorts there was erected a separate gas-producer,
so that even one set of eight retorts might alone be used if thought
necessary.

[Illustration: GAS RETORTS WITH REGENERATIVE FURNACES .--GLASGOW
CORPORATION GAS WORKS.]

In Figs. 1 and 2 of our illustrations, the general arrangement and the
relationship of the gas producer, the regenerators, and the retorts to
each other are clearly shown. It was a sort of _sine qua non_ of the new
method of firing the retorts that the producer should be in as close
proximity as possible to the place where the gaseous fuel was to be
used, and it was concluded that the most convenient situation would be
immediately in front of its own set of eight retorts, and with its top
on a level with the working floor of the retort house. To place it
in such a position meant a good deal of excavation, which was also
required, however, for the regenerator flues. The excavation was carried
down to a depth of 10 ft. below the level of the retort house floor, and
as a matter of course the operation of underpinning had to be resorted
to for the purpose of carrying down the foundations of the division
walls, which, together with the main arches and the hydraulic main, were
in no way otherwise disturbed. As in most new inventions, a good deal
of difficulty was experienced at first in connection with these gas
producers and heat regenerator furnaces; but by dint of application and
by the adoption of modifications made here and there in the arrangements
from time to time, as also by a determination not to be beaten, although
often disheartened, Mr. Foulis was ultimately rewarded with complete
success. The new system of firing being made so simple that there was
scarcely any possibility of failure likely to arise in ordinary practice
if it was superintended with but a moderate amount of care.

[Illustration: _Fig. 3._]

The results which were obtained in course of time with four ovens, or a
total of 32 retorts, were so exceedingly promising that it was forthwith
resolved to extend the new mode of firing to the whole of a double bench
of twelve ovens, now containing 96 retorts; and all the improvements
which had suggested themselves during the working experiments with the
four ovens were adopted from the first in the reconstruction of the
remaining eight ovens in the bench. More recently the regenerator system
has been applied to other 22 ovens, or 176 additional retorts, being the
whole of one of the main divisions of the retort house; and during the
very depth of the present winter, when the demand for gas was at its
greatest height, all the retorts of the converted or "Siemens" settings,
amounting to 272, were in full working activity, in which condition they
still remain. It is intended to make another very considerable extension
of the heat regenerative system of firing during the ensuing spring and
summer. The reconstruction of the present year will extend to the ovens
of seven retorts each, giving in this case eighty gas fired retorts; and
to twenty ovens of five retorts each, which will become sixteen ovens,
each having eight retorts, making 128 retorts in this division, and the
total being 208 retorts in place of 170 in the same amount of space. It
is confidently anticipated, therefore, that by the month of August of
the present year, 480 full sized retorts will be available for working
out the new method at the Dalmarnock Gas Works. Furthermore, the
confidence which has been inspired in the minds of the members of the
Glasgow Corporation Gas Committee and their engineer regarding the
actualities and possibilities of the Siemens system of firing gas
retorts, in its most improved state, is such that arrangements are
being made for starting shortly to apply it throughout at the Dawsholm
Station, which is situated in the suburban burgh of Maryhill, and some
four or five miles distant from the Dalmarnock Works in a northwestern
direction. The station just named, which is also a very large one, will
probably require two years for its conversion.

We shall now give some account of the structural arrangements adopted
for producing cheap gaseous fuel, and for turning that fuel to the
greatest advantage in firing the retorts for the purpose of carbonizing
the cannel coal used as the source of the gas.

The gas producer, which is represented in vertical section in Fig. 2, is
a cylinder of brickwork inclosed in a casing of malleable iron. It is 7
ft. 6 in. deep, and 3 ft. in diameter, which becomes reduced to 20
in. above, where it is closed by means of a cast-iron lid, which is
continuous with the floor of the retort house. There are no firebars
at the bottom, so that the fuel rests on a floor of firebrick. At the
bottom of the walls of the producer there are several holes about 1 ft.
in length by 6 in. in height. By means of these openings any clinker
that may form and the ashes of the spent fuel can readily be withdrawn.
They also allow of the admission of air to maintain the combustion in
the lower portion of the mass of fuel; and at each opening there is a
malleable iron tube for delivering a jet of steam direct from a steam
boiler. We shall subsequently explain the functions performed by the
steam.

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