The Sun.
London, England, 1847-05-04 00:00:00

Select Committee on Group No. 49.

Mr. Christie discharged ; Viscount
,Newport selected, and
added to the Committee.
Select Committee on Group No. 7.
Mr. iiorsman discharged; Mr. Stanstield selected, and
added to the Committee.
- - -

The Select Committees on the Groups Nos. 4, 29, 36, 37,
45, and 46, will be selected from Panel No. 6, which will be
required to be in attendance during the week commencing
Monday, May 17.

PANEL No. VI.
Mr. Adderley Hon. 0. Duncombe
Mr. Ainsworth Hon. G Fitzwilliam
G.

Mr. Alija
Mr. Antrohus

Mr. Halo
Mr. J. Heatheoat

Mr. Arkwright 3lr. E. Heneage
Mr. J. Bailey, jun. Mr. F. Hodgson
MT. Baine Sir Denis Le Marchant
Mr. H. B. Baring Mr. Mundy
Mr. tiaskerville Right Hon. J. Nicholl
Major Beresford Mr. S. O'Brien
Mr. Blewitt ' Colonel Peel
Mr. Bowes Mr. Roebuck
Mr. Boyd Mr. R. Scott
11r. Brocklehurst Mr. J. A. Smith
Lord E. Bruce Viscount Somerton
Mr. Buckley Mr. Sotheron
Viscount Castlereagh Sir S. T. Spry
Sir W. Clay Mr. E. Stanley
Lord A. Conyngham Sir G. Strickland
Marquis of Douro Lord J. Stuart
Mr. Duff Mr. Thornhill.
Hon. A. Duncombe

INSTITUTION OF CIVIL
ENGINEERS.

APRIL 27.—Sir John Rennie, President in the chair.
The paper of the evening was " On the laws of iso-
chronism of the balance-spring as connected with the
higher order of adjustments of watches and thermome •
ters;" by Mr. C. Frodsham, Assoc. Inst. C. E. The
first portion gave an historical sketch of the horological
inventions and writings of the artists of the eighteenth
century, which appears to constitute the basis of all the
knowledge possessed in the present day, and the princi-
ples of whose school were still invariably followed in the
construction of both watches and chronometers of the
better sort. It was admitted, that by the aid of machinery
and the practical skill of the workmen the separate pieces
of clocks and watches were now produced in a high state
of perfection; but it was contended that horology, as
a science, had declined since the days of Hooke,
Beruouilli, Sully, Graham, Harrison, Camus, Mudge,
Ellicot, the two Arnolds, Earnshaw, Le Roy, I3erthoud,
and others, whose splendid talents and scientific attain-
ments were all devoted to the elevation of the art of
constructing time keepers. Among these, Dr. Hooke
appears to have been the first to bring the force of acute
reasoning and pure mechanical genius to bear upon the
practice of the art, and his experiments upon the pen-
dulum, and the application of the balance-spring, which
latter unquestionably- laid the foundation of the chro-
nometric art. It is evident that he partially raised
the veil which concealed the laws of the isochronism
of the spiral spring, as is demonstrated by his
expression "ut tensio, sic vis," and it is extra-
ordinary that so plain a hint was not immediately
seized upon by the able men who succeeded him.
Arnold appears to have been the first who really prac-
tically comprehended the subject, and in the course
of his researches he invented the cylindrical spring
and compensation balance, which formed the com-
mencement of a new era in the science. The me-
rit of the discovery of the isochronism in France
was contested by Le Roy and Berthoud. Bernouilli
noticed in a paper read to the Academie in 1747, the
fact of the loss of elastic force in balance springs from
exposure to heat; and the experiments of Berthoud
demonstrated that, in passing from 22 degrees to 92 de-
grees of Fahrenheit, the loss per diem was 6 mins. 40
secs. The paper then considered generally and techni-
cally the subject of the isochronism of the_balance-
spring, enunciating isochronism to be an inherent
property of the balance-spring, depending entirely
upon the ratio of the spring's tension, following the
proportion of the arcs of inflection; a balance-spring,
therefore, having the progression required by the
law of isochronism, will preserve that property,
whether it be applied to a balance making quick or
slow vibrations. The elastic force of balance-springs was
considered as constant, because the action is by a
number of consecutive impulses following each other in
such rapid succession as to constitute an uninterrupted
and continuous force. This is shown in considering the
accelerated and retarded motion of the balance, when,
by following it through an entire arc of vibration, it
will be seen that if the balance be moved over a given
pumber of degrees, the spring will be wound into a
certain tension, and has acquired a certain elastic force
due to the angle over which it is inflected. This
elastic force being then transferred to the balance,
it will be exerted in overcoming its inertia, and at
the expiration of the first period will have communi-
cated a slight motion to it. During the next pe-
riod, its state will be that of comparative and not ab-
solute inertia (for it decreases as the motion increases),
whence it follows, that as the spring's force is exerted
against a body in motion instead of at rest, it will ne-
cessarily accelerate progressively the motion the balance
had previously acquired, until the spring arrives at the
point of quiescence, where, having lost all its elasticity,
it ceases further to urge the balance, and a new relation
of power and resistance takes place. The spring's force
being transferred to the balance, it assumes a new cha-
racter, has acquired sufficient momentum to carry it
through the second half of the vibration, and to in-
flect the spring over an angle equal to that first
passed over, and to give it the requisite tension
to commence a new vibration ; particularly as during
the second half of the vibration the spring has
so little tension that its force retards but slightly the
motion of the balance. After much acute reasoning upon
this position, illustrated by numerical examples, the
author proceeded to describe the helical and the flat
coiled springs, which are used in chronometers and
watches, and the manner of regulating their action so as
to take advantage of the isochronism, instancing the ad-
vantages to be derived from the innate power pos-
sessed by an isochronal spring of resisting the influences
which cause a change of rate, such as change of position,
increased friction from dirt, or the viscidity of
the oil at low temperature. This was well illus-
trated by an example of three balls falling in equal times
through spaces regulated by the densities of the
medium--viz., in vacuo, in air, and in water, wherein
they traverse spaces equal to the squares of the times.
So it was argued it was with increased friction in watch
work ; for the elastic forces of the balance-spring being
constantly proportional to the angle of inflection, what-
ever was the amount of friction, the law of isochronism
remained unchanged, and friction was only an adventi-
tious circumstance, which affects the extent of the arc
of vibration, but not the time of its description. The
discussion upon this interesting paper was deferred until
the next meeting, on Tuesday, May 4, when the paper
read will be " An Account of the Progressive Improve-
ments in Sunderland Harbour, and the River Wear ;"
after which the monthly ballot for members will take
place.

THE VIRTUES OF WEALTH.—THE WAY OF THE
WORLD.—The world is full of conventional hypocrisy. It
would seem to be the aim of a large portion of the human
family to practice falsehood upon themselves—to see
Now far by lying conventionalities they can impose
upon their own judgments, and perpetuate delusion. A
man, whose life has been stamped an over with unmiti-
gated selfishness, after having enjoyed the consideraAh
tion which wealth or connexion commands, dies. ,
there is mourning, as if a star had fallen fromsoci et heaven!
Poverty has lost a friend—virtue a defender, y a
model! And all this falsification is tolerated because
conventional. In such a body as the Congress of the
United States, there are representatives of all classes and
habits. Without offence, we may say that the mere fact of
being a member is not prima facie evidence of capacity, ho-
nesty, or purity. Vice, under its grossest forms, may find
votaries in an American Congress. But, it is somewhat re-
markable that a dishonest or debauched member never dies
" Death loves a shining mark," and every member stricken
by his dart is sainted for his. virtues. Whatever the rotten-
ness within, the sepulchre without is polished. " The me-
mory of the wicked shall rot," said Solomon, the memory
of the wicked is blessed by conventional hypocrisy.
National Era ( Washington.)

GLASGOW COTTON MARKET.---ARIL 30.—1 n con-
sequence of the dullness and downward tendency of the yarn
market and the tightness of money, our cotton market has
been very quiet—almost nothing selling except small par-
cels for immediate transmission to the mills. Prices are very
irregular.— Scotck Reformers' Gazette.
COAST OF FRANCE.--The Commissioners of Cus-
toms have issued directions to the collectors and comptrol-
lers of the several ports throughout the kingdom to cause
copies,of a notice which has been furnished to them, a
re-
specting alterations in the lights on Cape Frehel and on.,Lla
Four Ruck, on the coast of France, to be exhibited in
conspicuous place in the Custom-houses of their respective
ports, for the information of masters of vessels and
ail
ties concerned.