518 
WALTORE 
[ March 29, 1883 
THE MINok PLANET No. 228.—The nearest approach to the | combustion under the boiler, applied equally to the thermo- 
earth’s orbit made by any one of the 232 small planets so far 
known appears to occur in the case of No, 228, discovered by 
Herr Palisa at Vienna on August 19, 1882. At the perihelion 
point this planet may be distant from us only 0°662 of our mean 
distance from the sun, and on this account would prove a 
favourable object for a determination of solar parallax. But 
unfortunately the brightness of the planet at discovery was only 
12°5m., though the mean anomaly was then 14’, or the perihelion 
passage took place five days subsequently. Hence it is very 
questionable if such an object could be utilised for the purpose. 
No. 132, £thra, has the smallest perihelion distance (1°6038), 
but in consequence of the large angle between the lines of nodes 
and apsides, and an inclination of nearly 25°, this planet is much 
further from the earth’s track at perihelion than No. 228. 
Andromache, No. 175, recedes furthest from the sun, the distance 
at aphelion being 4°7234, or within 0°48 of the mean distance of 
Jupiter. 
Binary STars.—According to Dr. Doberck’s orbit of y 
Coronz Borealis, this very difficult object should now be 
measurable with our larger instruments, For 1883°5 the calcu- 
lated position is 123°, and the distance 0°34. This object was 
single, with the great refractor at Washington, from 1875 to 
1879. In June, 1881, it was pronounced round, or doubtfully 
elongated, by Mr. Burnham, who remarks, ‘‘Ir has been appar- 
ently single with all apertures since about 1871.” Doberck’s 
period of revolution is 954 years: periastron passage, 184377. 
The following calculated angles and distances of several uther 
binaries may serve for comparison with observations :— 
Epoch. Star. Position. Distance. Sees 
1882°5 ... » Cassiopeize 1633 5°52 ... Doberck. 
s 161°8 5°38 =... Duner. 
1882°5 ... ~ Bootis 268°9 3°56 .. Doderck. 
1883°5 ... A 267 6 3°20 50 
1882°5 ... w Leonis 86°5 0°60 55 
188375 ... a Oo o-6r PA 
1882°5 ... 7 Corone Bor.... 1409 O51 2p 
1882°5 ... ¢ Herculis 105°9 1°43 os 
1882°5 ... «” Herculis 297°3 O88) ee ns 
1882°5 ... 70 Ophiuchi 63°5 2°98 ... Tisserand. 
ELECTRICAL TRANSMISSION OF FORCE 
AND STORAGE OF POWER? 
D*: SIEMENS, in opening the discourse, reverted to the 
5 object the Council had in view in organising these occa- 
sional lectures, which were not to be lectures upon general 
topics, but the outcome of such special study and practical 
experience as Members of the Institution had exceptional oppor- 
tunities of acquiring in the course of their professional occupa- 
tion. The subject to be dealt with during the present session 
was that of electricity. Already telegraphy had been brought 
forward by Mr. W. H. Preece, and telephonic communication 
by Sir Frederick Bramwell. 
Thus far electricity had beea introduced as the swift and 
subtle agency by which signals were produced either by mecha- 
nical means or by the human voice, and flashed almost instan- 
tanevusly to distances which were limited, with regard to the 
former, by restrictions imposed by the globe. To Dr. Siemens 
had been assigned the task of introducing to their notice electric 
energy in a different aspect. Although still giving evidence of 
swiftness and precision, the effects he should dwell upon were 
no longer such as could be perceived only through the most 
delicate instruments human ingenuity could contrive, but were 
capable of rivalling the steam engine, compressed air, and the 
hydraulic accumulator, in the accomplishment of actual work. 
In the early attempts at magneto-electric machines, it was 
shown that, so long as their effect depended upon the oxidation 
of zine in a battery, no commercially useful results could have 
been anticipitated. The thermo-battery, the discovery of Seebeck 
in 1822, was alluded to as a means of converting heat into 
electric energy in the most direct manner; but this conversion 
could not be an entire one, because the second law of thermo- 
dynamics, which prevented the realisation as mechanical force 
of more than one-seventh part of the heat energy produced in 
* Abstract of lecture given at the Institution of Civil Engineers on 
March 15 by Dr. C. William Siemens, F.R.S., M.Inst.C.E, Revised by 
the author. 
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| 
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i 
electric battery, in which the heat, conducted from the hot points 
of juncture to the cold, constituted a formidable loss. The electro- 
motive force of each thermo-electric element did not exceed 
07036 of a volt, and 1800 elements were therefore necessary to 
work an incandescence-lamp. 
A most useful application of the thermoelectric battery for 
measuring radiant heat, the thermopile, was exhibited. By 
means of an ingenious modification of the electrical pyrometer, 
named the Bolometer, valuable researches in measuring solar 
radiations had been made by Prof. Langley. 
Faraday’s great discovery of magneto-induction was next 
noticed, and the original instrument by which he had elicited 
the first electric spark before the members of the Royal Institu- 
tion in 1831, was shown in operation. It was proved that 
although the individual current produced by magneto-induction 
was exceedingly small and momentary in action, it was capable 
of unlimited multiplication by mechanical arrangements of a 
simple kind, and that by such multiplication, the powerful 
effects of the dynamo-machine of the present day were built up. 
One of the means for accompli-hing such multiplication was the 
Siemens armature of 1856. Another step of importance was 
that involved in the Pacinnoti ring, known in its practical appli- 
cation as the machine of Gramme. A third step, that of the 
self-exciting principle, was first communicated by Dr. Werner 
Siemens to the Berlin Academy, on January 17, 1867, and by 
the lecturer to the Royal Society on the 4th of the following 
month. This was read on February 14, when the late Sir 
Charles Wheatstone also brought forward a paper embodying 
the same principle. The lecturer’s machine which was then 
exhibited, and which might be looked upon as the first of its 
kind, was shown in operation; it had done useful work for 
many years as a means of exciting steel magnets. A suggestion, 
contained in Sir Charles Wheatstone’s paper, that ‘‘a very re- 
markable increase of all the effects, accompanied by a diminu- 
tion in the resistance of the machine, is observed when a cross 
wire is placed so as to divert a great portion of the current from 
the electro-magnet,” had led the lecturer to an investigation read 
before the Royal Society on March 4, 1880, in which it was 
shown that by augmenting the resistanc+ upon the electro-mag- 
nets a hundredfold, valuable effects could be realised, as illus- 
trated graphically by means of a diagram. The most important 
of these results consisted in this, that the electromotive force 
produced in a ‘‘shunt-wound machine,” as it was called, in- 
creased with the external resistance, whereby the great fluctua- 
tions formerly inseparable from electric-are lighting could be 
obviated, and that, by the double means of exciting the electro- 
magnets, still greater uniformity of current was attainable. 
The conditions upon which the working of a well-conceived 
dynamo-machine must depend were next alluded to, and it was 
demonstrated that when losses by unnecessary wire-resistance, 
by Foucault-currents, and by iniuced currents in the rotating 
armature were avoided, as much as 90 per cent., or even more, 
of the power communicated to the machine were realised in the 
form of electric energy, and that vice vers@ the reconversion of 
electric into mechanical energy could be accomplished with 
similarly small loss. Thus, by means of two machines at a 
moderate distance apart, nearly 80 per cent. of the power 
imparted to the one machine could be again yielded in the 
mechanical form by the second, leaving out of consideration 
frictional losses, which latter need not be great, considering that 
a dynamo-machine had only one moving part well balanced, and 
was acted upon along its entire circumference by propelling 
force, Jacobi had proved many years ago that the maximum 
efficiency of a magneto-electric engine was obtained when 
; e w 
OR Ge 
which law had been frequently construed by Verdet (‘* Theorie 
Mécanique de la Chaleur”) ani others to mean that one-half 
was the maximum theoretical efficiency obtainable in electric 
transmission of power, and that one-half of the current must 
be necessarily wasted or turned into heat. The lecturer could 
never be reconciled to a law necessitating such a waste of energy, 
and had maintained, without disputing the accuracy of Jacobi’s 
law, that it had reference really to the condition of maximum 
work accomplished with a given machine, whereas its efficiency 
must be governed by the equation 
Gly 
EW 
From this it followed that the maximum yield was obtained 
= nearly 1. 
