ducing an arc between the two conductors two wires were attached to them, so that their extremities were 22 millimètres apart. When the pressure in the mains reached 18,000 volts, a momentary arc was started, which was immediately extinguished by the melting of the safety fuse.

To ascertain the influence of the secondary current on a telephone circuit, the latter was arranged on the same posts at equal distances from the two wires. It is to be noted that the secondary conductors were not arranged as shown in Fig. 1, but in four parallel lines, in order to get as great a length of wire as was possible in the limited space. The working of the telephone was quite satisfactory, although a slight noise, due to the proximity of the secondary conductors, could be clearly distinguished. The tests were only of a qualitative nature, but they clearly established that the working of a telephone between Heilbronn and Frankfort can be perfectly well carried on.

The action of the fuses proves that a short circuit, such as may occur through the breaking of a pole or any other accident, will instantly cut off the current. The insulation under the most unfavourable circumstances that could be brought to bear (drenching insulators and posts with water) was practically perfect. It is impossible that any accident could happen through the breaking of a wire, and the installation can therefore be carried out with perfect security.

The experiments just described were made with an ordinary alternating current, but in the Lauffen installation it is intended to employ a totally new system, depending upon what has been termed a rotating' or "multiple phase," instead of an "alternating" current. This system is the invention of Herr von Dobrowolsky, head engineer of the Allgemeine Elektricitäts Gesellschaft. The current he uses is practically a combination of alternating currents, in which the phases are displaced with regard to each other. As a general rule, three alternating currents are employed, though in special cases the number is increased. The currents are produced by a specially constituted alternator excited by a continuous

at 25,000 volts, which is conveyed to Oerlikon, a|
distance of 13 miles (22km.), by means of four
conductors of copper, 16in. (4mm.) in diameter,
supported on Johnson and Phillips oil insulators.
The loss in the wires is 14 per cent., one-eighth
of that allowed for in the Lauffen-Frankfort in-
stallation. The Municipal Electric Works at Heil-
bronn, 12 miles from Lauffen, are also to be carried
on on the same principle, and, in fact, the identical
machine used in this case will be employed for
the longer transmission to the Frankfort Exhibition.
From the above remarks it will be seen that the
employment of the means adopted will enable the
project to be carried out with perfect security,
and that its satisfactory working can be safely
relied on.

SHOP.*

Fig. 3.

Fig. 2.

In the machine shop the workman is supposed think, and he is not expected to let his hand pull his common-sense around much. In the machine shop a machine is not used to drill similar holes under the same conditions for many months without a "let-up," and so many times it would be more bother to set a stop than to get along without it.

Some establishments run both machine shop
and factory, and some of these places seem
to know a great deal more about managing
the factory than the machine shop, and so
it is amusing sometimes to notice the way
things drift around. As I said before, the factory
plan is to hire "hands" to do the pulling around,
and confine the "think" to another department.
Now, when they undertake to apply this plan to
the machine shop the fun commences. If a "hand"
is started at drilling a tin. hole, perhaps in fire
minutes it is done, and then he applies to the think
department to be started again. This makes the
RILLING operations in most machine shops think department very busy, and so from time to
using jigs as far as is practicable, and then by while the think department will outnumber the
proper conveniences for holding work. I have other, and then, perhaps, the manager will "catch
never seen drill presses supplied with proper rig. on" to this very bright idea. Let the man who
ging. For many jobs of drilling we need something thinks, not only think, but pull too, and, if neces
a like such rigging as is used on the planers, but we sary, pay him both men's wages. Now, this
never see such rigging, and I would like to know factory manager has completed his circle of "im
why. A few years ago a new Gould and Eber-provements," and has got right back where he
hardt drill-press was bought, and set up in the shop started from. He could have gone into grand-
where I was working. I noticed that there were
father's shop and learned this on the start. The
pins or hooks cast on the machine for holding bolts long and short of it all is this: It is just as sensible
to pay one man to think as another, the conditions
remaining the same.

current, the number of contact rings on the CONVENIENCES IN THE MACHINE
alternator corresponding to the number of currents
used. When three currents are employed the
angular displacement between each set of phases
is 120°. The current impulses are made to follow
one another in a fixed order-e.g., either 1, 2, 3;
1, 2, 3; 1, 2, 3; or 3, 2, 1; 3, 2, 1; 3, 2, 1; and they
consequently produce a rotating magnetic field.
A "rotating" current can therefore, unlike an
"alternating" current, be considered to possess

direction of flow. The difference between the three
classes of current, " continuous,"
""alternating,'
and "rotating," can be clearly brought out by the
action of a compass needle when surrounded by the
conducting circuit. When the current is continuous,
the needle takes up a position determined by the
resultant of the earth's field and that due to the

circuit, and remains then at rest. If the current is
alternating, the needle oscillates about the position
it would take under the influence of the earth's
field alone. When the current is rotating, the
needle commences to rotate on its pivot. If the
compass needle is replaced by an iron cylinder, a
" rotating current motor is obtained, which has
neither winding, collector, nor contact ring in its
moving part, and the armature of which (if
it may be called) is
80
not included in

the circuit. Motors made on this principle,
like continuous current motors, will start
with a load, whereas alternating motors will only
start from certain positions, even when without
load. The "rotating current" motors, moreover,
are not larger than those for continuous currents
for the same capacities, and they run perfectly
quietly. In these respects they are distinctly
superior to alternating current motors. They are
extremely simple in construction, and work with
perfect reliability; they are,
synchronous, and can be regulated to run at very
of course, not
nearly constant speeds between light and full loads.

As I am informed by Herr Dobrowolsky, the

efficiency for a two-horse "rotating current" motor was found to be 82 per cent. between the outputs of 1 and 24H.P.

by the head.

keeping any bolts around the drill-presses, I was
As in this shop they were not in the habit of
somewhat interested to see if they were going to
take this good suggestion.

I did not see anyone "catch on," and I do not
think to this day that these pins have been intro-
duced to a bolt of any kind; and more than this,
there is not a decent set of drill-collets in the shop,
or a good drill-chuck that can be used on this drill-
press. Good machine tools cannot be appreciated
without proper conveniences to go with them. I
believe that a firm can afford to supply conveniences
for use on them, so the reason must be insufficient
thought-or, in other words, neglect. I believe it
would be a profitable move if there was some
system established in shops in regard to this matter.
Probably it would not be necessary to have com-
plete rigging for each machine. There should be
good bolts arranged the same as for the planers, also
good straps, knees, jack-screws, V blocks, parallels,
grips, centre, set of collets, and a good drill chuck
near the machines (not in the tool-room), where they
These things should have places provided for them
can be kept clean, and above all it should be some-
body's business to see that these things are kept in
their places and clean.

The portable drill-press has its uses, and I believe in connection with this that electricity is destined to play a part. Perhaps not play, but pull. The advantage of electricity for this purpose lies in the convenience of conveying power to the drill. When electricity is used more for light in the shops, per haps it will be used for this purpose also. Elec tricity would be a good means of conveying power to the spindle of a radial drill, for it would do away with a large amount of gearing, and so cause less vibration. The wires could trail from the ceiling, and would not interfere with any movement of the arm or slide.

In Fig. 2 I show a graduated dial that has been in everyday use for a long time, and to say that it is convenience is to say very little. The cross-scre of these lathes are eight pitch, and so eight division gives us 64ths. I use the plain friction calipers, and just round the work so as to caliper it, then take the size from the calipers with a scale, I then know guess for finer points, so that I find it safe to come how much is to come off by 6iths, and I find I can within three or four thousands of the size, the first try by this means; this helps, but this is not alte use by any means. It is useful for setting the In Fig. 1 I show an adjustable knee, which is lathe for tapers, for setting the lathe straight for The "rotating current" transformer transforms would often fondusif and wa for plaing the We can rough out a taper hole by its use, and de useful often drilling also I screw-cutting, for boring holes and recessing the all three currents together. It consists of three cores connected together at one end, the other purpose of weakening the casting at that point so lots of things "too numerous to mention." The extremity of each being attached to an iron ring. as to allow of clamping. I would also counterbore pointer shown at A is only a piece of sheet bra The apparatus, therefore, resembles an iron wheel will be sure to come on the largest diameter, sleeve to keep it in place. This plan is so simple and or scrape a little clearance at B B, so the contact bent around so as to have enough friction on the with three spokes. On each core there is a primary have already given a scheme for a graduated dial good that it has tempted me to try again. I belie and secondary coil. The whole arrangement is for drill presses. Some such plan is a great conthe dial should be the adjustable part. immersed in oil, as above described. In driving venience in the machine shop. In the factory a My design is shown in Fig. 3; a side view of the motors each of the three conductors has to be connected to the coils of the motor fields. Arc lamps supposed to think. There is some owo else furnished divide the same as Fig. 2. I would turn a journal "stop" is a better plan, for there workmen are not dial is shown at B. This, if the screw is 8, I would and incandescents are connected in equal numbers for this purpose, who sets the machines, and so the on the hub of ball crank to fit hole in dial tight, and across each pair of the three conductors. part till they get things better perfected, and then shown. workmen are only expected to furnish the automatic after graduating the dial I would split it as they will dispense with him. I say it is better to have a stop for the factory, and it is best to design this three times stronger than nice," letting nice DIET AND ANIMAL TEMPERATURE be the limit of the strength of a human being, then when the stop should act it is pretty sure to do so. QUESTION has been put to us by a By A MECHANIC. Extracted from the American Machinist, the animal temperature of persons who subsist on

An installation on this system is in process of erection for transmitting water-power at Bülach the Oerlikon factory. The available power is to 500H.P., and drives four turbines, one of Rerves as reserve. Each of these is coupled to a "rotating current" dynamo; the rether supply 4,000 ampères at 50 volts. nt is transformed to one of 8 ampères

A

No. 3.

No. 2.

No 1.

will be seen that every kind of surface work, such as straight edges, snap and other gauges, punches, dies, calipers, test blocks, &c., may be ground.by means of these two fixtures alone.

The next fixture to be noticed is the Universal cutter and reamer head, which, like the vice, is secured to the surface-grinding table by standard tongue and groove, and is capable of the same wide range of adjustment in all directions and at every angle. This head carries a swivel stud or clamp, having an index rotating in a graduated arc of 90°. This clamp stud forms a rigid socket for the various cutter mandrels, studs, and other fixtures, as also attached; all of which can be as fully adjusted as the fixtures previously described.

research. In 1869 Dr. B. W. Richardson, in one of T adopted by the Garvin Machine Co., of New the bar to which the reamer grinding centres are

York, for grinding various machine tools. Refer-
ring to figures in detail, we first notice the surface-
grinding table or attachment, shown in engraving, The Universal finger-bar is clamped firmly to
and having the vice holding a piece of work in lugs, cast solid to the spindle-head and projecting
process of grinding attached thereto. This attach- on both sides of the spindle. The lugs are bored to
ment is secured to the cross-slide block by means of receive a swivel-clamp stud, which may be located
a dovetailed plate that is itself both a slide and to either right or left of the spindle, and also on
swivel-plate, and is firmly clamped to the cross- either upper or lower face of both lugs. Through
slide block by means of a single cam, the handle of this clamp we may either slide or swivel the Uni-
which may be seen in cut at right hand of slide-versal finger-bar in every conceivable position. The
block. The cross-slide being a solid part of the finger or tooth-rest being secured to its bar by
knee, which moves vertically upon the face of the means of similar devices to those just noted, it will
pedestal, controlled by means of a screw and hand be readily seen that there can be no condition or
wheel, plainly shown in cut, it will be obvious that position in cutter grinding to which this finger
by use of the vertical and cross-feed screws, cannot be easily set to form the proper tooth-rest,
together with the swivel-slide plate, the surface- and the whole device is under control of a single-
grinding attachment can be set at any elevation or fork wrench.
position, in and out, and also permits the surface-
table or slide to be moved in every direction
horizontally, and can also be entirely reversed, if
desirable, to bring handle around to the opposite
side. It will be seen also that the table is provided
with two actuating shafts placed at right angles to
each other, the ends of both being squared to fit
the same wrench or handle. By this arrangement
all cramped positions for manipulation are avoided,
and overhanging work may be ground without
interference. Suitable clamping devices are pro-
vided to firmly secure each adjustment when pro-
perly set. The table is also provided with three
T-slots, to which the vice and other fixtures are
accurately tongued, and they are also to be used by
means of bolts, straps, or other devices to secure an
endless variety of work direct to face of table, which
will take in work 10in. long by Sin. wide, or even
more.

The vice, being also a surface grinding adjunct,
comes next in order of mention. With detachable
tongues fitted to both miller and grinder, each
operation may be performed, and is often desirable,
without starting the work in vice. By removing or
changing the tongues, we may set the vice length-
wise, cross wise, or at any other desired angle, to
either the table or plane of emery wheel. Thus it

A hand-rest for patent cutter grinding, and also for turning off emery wheels with the diamond, is provided as a permanent fixture of the grinder, and is plainly shown attached to front of knee by means of spring washer, stud, and ball handle, and can be thrown up from position shown, and held firmly as may be desired in vertical position. Cut No. 1 shows the surface-grinding table holding a cutterdie in its bolster-plate, and secured to the table by means of bolts and the T-slots already described. The angle shown at the extreme right hand may be changed to the squared stem in front if desirable.

The frontispiece shows the table in same general position, but with vise set to hold a snap gauge for inside grinding. The feed is controlled vertically by the elevating screw and crosswise by the ball handle and cross-feed screw, as shown in cut. It is not necessary to have the work or slide set perfectly square to the emery-wheel for surface grinding. In fact, better work can be done, and more free cutting by the wheel, if the traverse of slide is set at a slight angle to the plane of the emery-wheel's rotation.

Cut No. 2 shows a method of grinding the slides of large straddle or face-mills. In this operation the cutter to be ground rests directly on the face of the surface grinding table, being held or centred by the

face-mill stud shown with its upper end projecting through the centre of the face-mill, and is screwed fast to the table by means of the central T-slot and a suitable bolt, for which the stud is threaded, the stud being drilled on one side for a capstan pín or rod by which the stud is screwed down to the table. The universal finger bar is shown with swivel stud clamped to the upper surface of the right-hand lug, with finger or tooth rest set in proper position for grinding. The surface grinding slide gives the required traverse, and the strength of cut is to be regulated by the common vertical adjustment. In this operation it is only necessary to set the machine so that the tooth rest face and face of cutter tooth to be ground shall be parallel to line of traverse.

Cut No. 3 shows the manner of grinding the spiral and other cylindrical faces of cutters, as follows: The universal cutter head is clamped to the surface grinding table by means of a T-slot and bolt, into the swivel head of which is clamped the cutter mandrel parallel to face of table, and upon which the cutter is to slide, either by means of cutter sleeve, or, if the hole in cutter is of same diameter, it may slide directly upon the mandrel. The tooth rest must be set with face parallel to the leading face of cutter, and central to the emerywheel, so that we may run by the end of cutter and change from tooth to tooth when the cutter is clear of the emery-wheel.

the socket a bearing and shoulder is provided, to
which the tooth rest carrier is closely fitted and
secured in any position around the socket centre by
means of a split clamp. This last device is a great
convenience in getting to grind, for the tooth-rest
being once adjusted to cutter, we have only to
slack off the split clamp and revolve the whole
tooth rest about the socket to obtain the proper
clearance from the next tooth, which being done,
set up the clamp-screw, and the adjustment is
complete. Cut No. 7 particularly shows this
fixture in use for grinding the sides of butt mills.
In this operation the ordinary tooth-rest is slid back
out of the way, and the surface slide set parallel to
the cross-feed slide, being used to obtain the neces-
sary traverse. Thus may be ground the longest
butt mills that could be practically useful.

ticular industry, what was the profit derived, and what had the consumer to pay? He was not not going to put before them any fanciful figures, but figures which were published, and which any. one could check. In Manchester a ton of coal produced 9,611c.ft. of 20 candle-power gas-rather in excess of the average of the country, which was not more than 15-candle power. From this it followed that in Manchester 1lb. of coal would produce 4.29c.ft. of gas; and if 4-29c.ft. of gas were burnt per hour, it gave an illuminating power of 17-2 candles. On the other hand, 1lb. of coal burnt in a boiler to produce steam would give in electrical energy in the form of a glow lamp, such as was used in houses, 48 candles; and in an arc lamp, such as was used for street lighting, 288 candles. So that they started with the fact that llb. of coal disCut No. 8 shows the butt-mill fixture properly set tilled into gas in Manchester gave a light of 172 for grinding the end teeth of the cutters. There candle-power; and llb. of coal converted into elecare several other ways of adjustment for perform-trical energy would give 48 candles with a glow ing this operation, but we have selected the above light, and 288 candles with an arc light. In Manbecause it gives the most clearance for the emery chester, during the twelve months ended March 30, wheel, which for this purpose will be found most 1890, the income derived from gas was £434,351, efficient in the dish or saucer form, and is used with and the expenditure was £360,804, showing that a its flat side towards the work. The surface slide is balance of just a little over £73,000 was derived to be set approximately square to the cross-feed from gas, which was devoted to paying interest on slide, and is to be varied from this position as the loans, depreciation, and cost of public lighting. The diameter, number, and angle of teeth may determine. cost to the Corporation of Manchester now of proThe exact position of the socket is also subject to ducing light equal to 4,000 candles by gas was 2s., the same conditions. and, having obtained a Provisional Order to enable them to erect a central electrical-generating station, the corporation were now considering whether they should carry it out themselves or transfer it to another body.

In grinding cutters of this kind be sure all sides are set up tight before starting to grind. The only Cut No. 9 shows the same fixture in position for point necessary to observe is that the support-recutting the end teeth of butt mills, the cuttering edge of the tooth rest shall be parallel with the head being swung around at a right angle to the leading tooth face. This being done, it may be previous position. The proper position of the buttreadily seen that all parts of the cutter must pass mill socket is to be determined wholly by the by the emery-wheel under the same geometrical diameter of the mill and the number of teeth. Care conditions during the process of grinding. should be taken when recutting not to force the grinding, as the operation, under the best conditions, generates much heat.

Cut 4 represents the grinder set and in the process of grinding the flutes of a tapered reamer. To set up for this process, having removed the cutter mandrel from the swivel head, slide off the adjustable or tail centre, pass the bar through the swivel, replace the tail centre, and having placed the work to be ground between the centres, the bar is to be clamped in any desired position, and, being controlled by the universal adjustment, we are enabled to meet any reasonable condition of position for reamer grinding. The universal head is also capable of being set to any position on the surface table. In grinding reamers the tooth surface to be ground should always be set parallel with the movement of the surface table and the tooth rest parallel to leading face of the tooth. Always pass the reamer from end under the emery wheel, and bring them cautiously towards each other, allowing them to barely touch, to find the highest point or end of flute, and elevate or depress the same, as may appear necessary, until both ends bear alike, after which proceed to grind the teeth.

FIG. 1.

The Cost of Electricity.

In connection with the cost of electricity there was more reliable and truthful information than there was, perhaps, as to anything else connected with electricity, and from figures in the possession of the Board of Trade, who had such a powerful control over the electric lighting interest that there could be no "hanky-panky" with their accounts, there was not a shadow of doubt that at the present moment the "Kilo-Watt," which was the Board of Trade unit of electrical energy, could be produced for 4d., which meant that as against 4,000 candles of light produced by gas for 2s., 4,000 candles could be produced by electricity in the form of the are light for 8d., and in the form of the glow lamp for 4s. Having shown that what was nominally 15 candle gas was reduced to 10 by reason of dirt in the burner, draughts, and that flickering of the

FIG. 2.

Cut No. 5 illustrates the proper position of the machine in process of grinding angular cutters. For this, the centres having been removed, the cutter stud is inserted in its place and swung to the desired angle, as indicated by the pointer and graduated arc. The tooth rest is to be according to general instructions already given, but always remember to keep tooth rest and leading face of for a lin. nipple, in such a manner that a pipe light prevented the combustion of the gas, and that tooth and slide parallel, the first two accurately and introduced would pass, not on a line with the radius, gas was being wasted by being left flaring unneces the latter approximately. By means of this and but about half-way between the axis of the 4in. sarily, Mr. Preece proceeded to argue that there similar studs of various diameters, the sides of the pipe and its walls; in other words, it would be on would be no such waste with electricity. Taking angular and face mills may be ground, the stud being swung up to a vertical position, bringing the a line with a chord of the circle. (2) One lin. the figures of the nine chief towns of this country, cutter sides into the horizontal, and the tooth rest end. (3) Two 4in. malleable iron caps, drilled and sumer for gas per light per annum was 95., wrought-iron nipple, 2in. long, lin. thread on one he showed that the average price paid by the conadjusted accordingly. Many more fixtures adapted tapped for a lin. pipe. (4) One lin. wrought-iron against 10s. for electric light, calculated on the to special cutters, or made according to the ideas of pipe, 24in. out to out, with a 3in. straight thread on 200,000 lamps at present in use in London. Those different mechanics, may be secured in the universal each end. (5) Two lin. iron caps. A hole, tin. in were rather startling figures, as most people were head after the manner already explained. Cut No. 6 illustrates a very simple and convenient diameter, is drilled in the end of one of these caps. under the impression that the cost of electric lightThe above order can be given literatim, and will ing was very much more than that of gas, and he way of holding large face mills to grind their be understood by the dealer, who will furnish, at a was very much surprised to find that in his own cylindrical tooth faces. This is accomplished by trifling cost, the materials, cut and tapped as house, where for the last eight years he had had an swinging around the surface grinding slide to an ordered. engine and accumulators and generated his own approximate right angle with the cross slide, with Fig. 1 shows how the whole is put together. The electricity, the price he paid for his lights amounted the cutter mandrel clamped in the universal cutter head horizontally, and the head itself secured to the numbers on the figure correspond also to the num-to less than 10s. per lamp per annum. surface slide in such position as will allow the Fig. 2 is an end section. A cork is inserted in 2 bers of the paragraphs of the order as given above. Revenue of the Electric-Lighting cutter to overhang the same. Then bring the and through it a thermometer, the bulb of which is centres of emery wheel and cutter on a level, for on a level with the interior pipe. The whole is which position the tooth rest is adjusted vertically supported on a few bricks at either end, and is kept instead of horizontally, as previously shown. The cutter slides, either directly or by means of the steady and in place by a couple of weights or half cutter sleeve, upon the cutter mandrel. In this bricks. It is heated by one or two Bunsen burners, matter we may grind mills up to 20in. diameter according to the temperature desired. (larger than are to be found in ordinary practice)

quite as accurately as are the smaller mills.

Cut No. 7 shows the manner of using the special

butt mill fixtures, designed for the grinding of small THE RELATIVE COST OF GAS AND
cylindrical and other shank cutters. This fixture
consists of a socket in which the shank of the cutter

THE ELECTRIC LIGHT.

volves, and is fitted to be clamped in the cutter MR. W. H. PREECE (chief electrician to the
1. and a tooth rest provided with universal
G. P. O.) last Friday delivered a very inter-
ment to take in cutters from the smallest esting address before the Incorporated Associa-
p to 2in. and 2in. in length. The shank tion of Municipal and County Engineers, at the
amed to our regular grinder mandrel Institution of Civil Engineers. Addressing the
y convenient size for the shanks of this members rather as a gas shareholder than as an
r). The lower end of this socket is enthusiastic electrician, he said the questions they
foot screw with lock nut, and can had to decide were principally such questions as the
as to raise the shank just clear of following: What was the capital involved in a par-
er, so that it can revolve freely and
socket. Upon the upper end of Chemical Section of the Franklin Institute.
A paper by H. PEMBERTON, JUN., read before the

Companies.

He had had tabulated the revenue derived by each of the London electric lighting companies per 33 wall lamps, by which it appeared that the Metropolitan derived a revenue of 128. per lamp, the Chelses Ss. 6d., the Kensington and Knightsbridge 9s. 2d.. the House to House 11s. 6d., the St. James's and Pall Mall 98. 6d., and a company in Brighton derived an average revenue of 8s. 6d., the mean revenue for 200,000 lamps in London being 10s. In Manchester, where gas was cheaper than in London, the average price paid per lamp per annum was 78. 6d., as against Ss. 4d. for the electric light. In London the Electric Supplies were charging 74d. in some instances and 8d. in others. In Bradford they commenced by charging 5d.; but they had now raised the price to 6d. In Newcastle-upon-Tyne they were charging the public 44d., and allowing considerable discounts on that 44d. to large users of electricity. In the case of the Post-office at Newcastle, for instance, there had been a discount of 20 per cent., so that in that town the cost of electric lighting very nearly approached the price of gas.

In Bolton, at Messrs. Horrocks's mill, which had for the last six years been lighted by electricity, the cost worked out at 48. Od. per lamp, as against 58. 6d. when they used gas.

In Manchester, again, there was under the Exchange a very large restaurant which used to be unbearable when lighted by gas; but with the electric light now the manager found that he was not only saving £800 a year in the cost of illumination, but that his business had doubled by reason of the atmosphere being cleared, so that people were able to eat their meals in comfort.

When the association visited the Naval Exhibition, they would see that the electrical energy used for the whole Exhibition was generated by one engine and one dynamo coupled together.

At Deptford they would find space for electrical machinery sufficient to light à million lamps, although at the present moment only about 200,000 were kept going. One of the greatest merits of electric machinery over gas machinery was the small space that was occupied by the former. Whilst a space of 100ft. by 50ft. was required for the machinery necessary to manufacture a million cubic feet of gas, the same space would contain electrical machinery sufficient to light up the whole of a big town.

The adoption of the electric light in houses would remove a source of deterioration to one's goods and chattels, to one's books and pictures; and it would do away with that which destroyed one's decorations and dirtied one's ceilings, and would introduce something which encouraged cleanliness, and which would add materially to one's comfort and cheerfulness, than which there was nothing which made a man pass through the world with comfort to himself, especially after meals. Nothing would add so much to the cheerfulness of this life as the electric light, and he felt quite satisfied himself that if he had not had the electric light in his house for the last eight years he would not have been addressing the association at that moment.

The Chief Controller of the Post-office told him that on Christmas Eve the electric light had enabled them to get through the work quicker than they had ever done before, and that it was equal to 200 men. In the Savings Bank Department of the Post-office the cost of the electric light had been paid for by the increased service that was got out of the staff there. It had diminished the number of hours of absence by two hours per head per annum, and that, put at 10d. per hour, the ordinary overtime rate in the Government service, amounted to a saving of £680 a year; and as the cost of the electric light was £700, it really amounted to £20 a year out.

It was argued by many that "the electric light is the lamp of luxury; we do not want this thing in our midst; it is only for the rich." He had endeavoured, to the best of his ability, to bring this subject before those present as a practical man dealing with practical men; and he wanted them, if they agreed with his conclusions, to try and persuade the different boards and corporations whom they represented to look at this matter of the introduction of electric light, not only from a financial point of view, but from a political as well as a sanitary point of view, and, above all, from a philanthropic point of view, as being not the lamp of luxury, but the poor man's light."

Again, it seems impossible to do away altogether

b
C= + n+cFn.
F F

It is, therefore, obvious that by making F as
a and n become
F F
great as possible, the terms
less important in comparison with c Fn.

That this result had been attained was evidenced by the great slowing of speed of the meter for a given current when the field was increased. In use, the field-magnet is sufficiently saturated to make an alteration of a few volts at the field-magnet terminals of very little effect.

Fig. 1 is a section. A is the armature; it is a cylindric copper vessel, closed at its upper end, except for a few holes. It is like an inverted claret glass, and is immersed in mercury, in which it revolves. It receives current from a heavy ring, B, of copper, the current passing through the mercury to the lower edge of A. It passes in a cylindric current sheet upwards through A, and passes from A through the mercury to C, a fixed At this upper part tube dipping into the mercury. there is quasi-solid friction, but it is very small. The armature is coated with insulating varnish and gives out current, and at these places it is nickel plated; hence, in the field there is no everywhere, except at the places where it receives current whatever through the mercury. A phospor bronze spindle gives motion to the counting arrangement. The spindle is in two pieces, so that the upper part may be insulated. It can be fixed rigidly to the fixed bracket when being carried cylindric poles, SN, form the two sides of the trough about. M is ebonite. SPQRN is a cylindric or tubular magnet wound with fine wire, W. The in which the armature revolves, and 7 or 8 watts are expended in maintaining between them an intense magnetic field. But this field is not uniform. The plan of the pole pieces, Fig. 2, shows a number of wooden plugs, between which iron poles project, so that every portion of the cylindric part of the armature passes from intense field to almost no field 10 times in each revolution, and the result is

ENGLISH MECHANIC AND WORLD OF SCIENCE: No. 1871.

that the Foucault current friction is about 25 times
the fluid friction.

In such an instrument, the smaller the clearance
thicknesses inside and outside A, the more exact
will the instrument be in its record. It can be
shown that the best results are obtained when the
thickness of the copper is equal to the two

clearances. Until the meter is manufactured in considerable numbers, the clearance will be much greater than it ought to be. In the instrument exhibited, the copper was much too thin and the clearance much too great, and yet:-1. It started with 0-2 ampère. This represented the error due to solid friction. 2. From 2 ampères to 100 ampères there was only one place (namely, at 10 ampères) where the error was so great as 1 per cent. 3. There was nothing to alter with time. 4. Temperature errors balanced themselves.-Extracted from the

Electrician.

THE

SCIENTIFIC NEWS.

HE ephemeris of Wolf's Comet for July 10 Berlin midnight is R.A. 1h. 15m. 88., N. Dec. 27° 15'; brightness, 3-30.

The approximate Greenwich mean time at which the spots on Saturn observed by Mr. Stanley Williams may be expected on the central meridian are for July 10-(1) 9h. 17m., (2) 10h. 14m., (3) 11h. 36m.

Another asteroid (No. 311) was discovered on June 11, by M. Charlois, of Nice. Prof. D. Kirkwood, in the Publications of the Astronomical Society of the Pacific, gives a list of asteroids arranged in ten groups according to the similarity of orbit. Jupiter is supposed to be responsible for the perturbations.

Dr. J. G. Porter, director of the observatory at Mount Lookout, Cincinnati, in a recent number of the Publications of that observatory, gives a series of charts and micrometrical measures of nebulæ made with the aid of the 11in. refractor during 1884-86. The larger portion of the nebula-about 105 altogether-are considerably to the south of the equator.

stars.

6,000 miles, occupying some 25 days. The
familiar term, immense," and those who would
like to make the trip should communicate with
surface geology of America (U.S.) is, to use a
Mr. F. S. Emmons, secretary of the International
Geological Congress, Washington.

of the Institution of Electrical Engineers and
Mrs. Crookes in the galleries of the Royal
A conversazione is to be given by the President
Institute of Painters in Water-Colours, Prince's
Hall, Piccadilly, on Monday evening, July 6.
published in quarto by the University Press, at
Prof. Sylvester's mathematical works are to be
the request of many of the leading mathematicians
of the two foremost English Universities and of
eminent members of the Academy of Sciences,

Paris.

French geologists have made several important
discoveries in Tunisia, and the latest is the jaw-
bone of a mastodon, which was found recently by
some ancient aqueducts.
M. Gaudry at Cheri-Chera, while examining
which furnished the fossil is believed to have
The extinct animal
been the Mastodon angustidens of Cuvier.

JULY 3, 1191.

London Chamber of Commerce, says that he is
Tivoli to Rome by means of a bare wire, and at
a pressure of 5,000 volts.
preparing to transmit 2,000 horse-power from

Stress" for his subject.
Prof. Rücker will deliver one of the evening
British Association, and has chosen "Electrical
discourses during the Cardiff meeting of the

perhaps the highest inhabited place on the earth
In Peru, near the village of Galera, which is
mountain peak for railway purposes. The tunnel
nearly 4,000ft. long is being bored through the
is about 600ft. above the perpetual snow-line.
more than 15,000ft above sea-level, a tunnel

"A8

is now published at its "own office," 326, High In this month's Knowledge (which, by the way, panion to Alpha Ursa Majoris, in which he says Holborn), Mr. Burnham has a note on the comthat observations made with the Lick telescope show clearly that the companion is moving round the principal star in a retrograde direction, Eyre Crowe, A.R.A., and the editor, Mr. and that the two form a physical system. Mr. the phosphorescence of gems under the electric It is rather singular that artists are not discharge in a high vacuum, Mr. Crookes finds more Kanyard, have interesting notes on It is stated that in pursuing his researches on tronomy as Taught by Academy Pictures." the light evolved to be of different colours accord- meeting of Wellington and Blücher, under an careful. The famous picture of the the Cape show a blue phosphorescence, those from pictures with a rainbow inside out are too ing to the origin of the stone. Diamonds from impossible arrangement of stars, may pass; but Brazil a red, orange, blue, or yellow, and those bad. Mr. Crowe's fault would be of no moment from Australia a yellow, blue, or green light. at all if the subject were not Horrocks and Crystalline alumina that is to say, the ruby, Venus, and the instruments the astronomer sapphire, and corundum-phosphoresce a deep employed. red, and give a spectrum of one crimson line. Uncut specimens of phenakite become yellow Yellow sapphire glows with a delicate lilac tint emerald from Ireland emits a deep red lustre similar to that of the ruby, but does not give the and blue under the discharge; while green crimson spectrum of that crystal.

menced, as the Bill has practically passed all
Bush to Cornhill will probably be soon com-
The Central London Railway from Shepherd's
development of electric railway schemes.
stages. We may shortly see

a considerable

J. G. Hagen, S.J., formerly of Madison, USEFUL AND SCIENTIFIC NOTES.
A work, the result of labours carried on by
Berlin. It is the work of 20 years, and will bear
Wisconsin, but now director of the Georgetown
the title of "Synopsis der Höheren Mathe-
Observatory, Washington, is to be published in

matik."

a

A Remarkable Run of Iron.-The Mance

Had the stack been

The death is announced from India of Mr. lona (Mich.) Herald says:-Stack No. 2, blast Norman Robert Pogson, Government astronomer No. 1, of the Antrim Iron Furnace, completed the at Madras. Mr. Pogson was formerly at the Radcliffe Observatory, Oxford, but for the last thirty years has been director of the Madras Observatory. He was elected a Fellow of the for snake-bite induces us to publish the follow- that time amounted to 66,347 tons of pig iron-s The difficulty experienced in finding a remedy days in blast, 1,050; and the total product during third year of its present blast April 15. Number of R.A.S. in 1860, and was in his sixty-third year ing, which we hope is true:-A curious instance daily average of 63 tons. A trifle over a year and when he expired on the 23rd ult. Mr. Pogson of one poison killing another is reported from half of this run-or, to be exact, 582 days of itmade several important contributions to astro-Yackandandah, Victoria, where Dr. Mueller has the stack was blown with a small Weimer engine, nomical literature, especially reports of results recently administered strychnine in cases of snake- 553 tons. The balance of the run-468 days-was obtained from observations at the Madras Ob- bite. A solution of nitrate of strychnine in 240 made with a large engine of the same make, during servatory. with a product of 32,326 tons, a daily average of He also discovered eight minor parts of water, mixed with a little glycerine, is which time the product amounted to 34,021 tons, & planets and twenty new variable stars, and added prepared, and 20 minims injected hypodermically daily average of 72 tons. To make this amount considerably to information regarding the fixed at intervals of 10 to 20 minutes, according to the of iron, 115,410 tons of ore was used, and 146,000 virulence of the attack. In some cases a grain cords of wood consumed. hours. The two poisons are antagonistic, and the engine, the total product would, of course, have of strychnine has been given thus within a few blown during the entire period with the large characteristic efforts of the strychnine only show been much greater; but the record is a remarkable themselves after the venom has been neutralised, one, nevertheless, and it is believed that no charcoal evinced by slight muscular spasms, and the in: stack in the United States has ever made so long s jections must then be discontinued, unless after run or so large an amount of iron with a single a time the snake-poison reasserts itself. So long as the latter is active, the strychnine can be applied in quantities which would be fatal in the absence of the virus. Out of 100 patients treated death, there was only one failure, and that arose this way, some of whom were at the point of from the stoppage of the injections after one and a quarter grain of strychnine had been admininjection, but Dr. Mueller chooses a part near istered. Any part of the body will serve for the the snake bite.

Dr. J. Merrifield, Ph.D., who died on Sunday last in consequence of a paralytic seizure, was for 30 years head master of the Plymouth Navigation School, through which many thousands of officers of the mercantile marine have passed to qualify for navigation duties. For twelve years he was a member of the Plymouth School Board, and rendered great service in various departments of science, especially in reference to meteorology and astronomy.

Prof. William Edward Weber, of Göttingen, the famous student of physical science, who died the other day in his ninetieth year, was the last survivor of those Liberals who turned out of their professorships by King were Ernest. Weber was restored to his chair at Göttingen in 1849, and held it for the remainder of his life. With Gauss he was one of the first to devise a practical electric telegraph, which was the earliest (1833) in which magneto-electricity was used, and his name has been employed in this country to designate the unit of

electric current.

The deaths of two well-known explorers are announced. Sir George Macleay did much to assist in opening up Australia, and Mr. Burdo, the Belgian, was one of the pioneers in the modern advance in Africa.

remedies in the workshop crop up now and then
It is rather singular how old and well-known
as scientific discoveries.
familiar white lead and oil, except that in the
shops they use linseed-oil. A plaster composed
Here is one the
of one part of carbonate of lead in two parts of
olive-oil applied to sprained joints is considered
Duhamel has been trying the effect in Paris on a
in Holland to be an efficacious remedy. Dr.
number of cases, most of which were sprains of
the ankle, and the patients were made to walk as
soon as the plaster and retaining dressings had
been applied.

in the Chemical News says: lining. bromides the other day, it occurred to me, as my A Substitute for Starch-Paper.-A writer break off my work to make more, that I might find starched paper was gone, and I was disinclined to qualitatively a mixture containing iodides and While analysing an efficient substitute in ordinary white writingpaper. I tried this after moistening with water, best starch-paper that ever was prepared; and why and found to my delight that it did as well as the of starch?" finished with size which contains a notable quantity not, seeing that in the process of manufacture, writing-paper-or, indeed, any common paper-is

in operation at the Burden Iron Company's plant at Troy, N.Y. It was constructed in 1851 by the late Largest Water-wheel. The largest and most powerful wheel in the world is a water-wheel Henry Burden, and is containing 36 buckets each 6ft. deep, and is so 1,200H.P., 60ft. in diameter, practically constructed as to be readily controlled an overshot wheel of by a lever, which gives it any degree of power 22ft. in width, and required. A wheel, thought to be the largest in the It is a cog-wheel 54ft. in diameter, 18in. face, and Dickson Manufacturing Company at Scranton, Pa world, but which will have to be acknowledged second at the best, was recently constructed by the 2.000 tons of sand per 24 hours, run at a velocity of has a capacity of 30,000,000gals. of water, and 10ft. a second on the inner edge of the buckets. It weighs 400,000lbs. The journals are 23in. in diameter and 3ft. 4in. long, and the total length of the

Geologists who can spare the time have an opportunity of studying their favourite subject in connection with the International Congress of convocation of Oxford University for grants of Sundry "free libraries" have to thank the Geologists, to be held in Washington, D.C., books printed at the Clarendon Press. from August 26 to September 2. train of vestibuled "Pullmans A special issued by that Press are generally worth having; Works lly forms a movable hotel) will leave Washington frequenters of free libraries. (which practibut we are afraid they will be little used by the September 3, and will travel over about Prof. Mengarini, of Rome, in a letter to the shaft is 23ft. 6in.