ily around the axle until the external pinion
is carried into engagement with gear I, when the shell is again locked
fast. The axle communicates motion through D, E, and P to the center
pinion, which in turn drives all the secondary pinions except F. If
the external pinion is applied to F, it will receive motion directly
therefrom; but if applied to either of the secondary pinions, it will
receive motion through or by way of the center pinion. It will be seen
that all the pinions are sustained and protected within the shell.

The essence of the invention lies in the introduction of the pinions D
and E between the axle and the series of secondary pinions to reduce
the speed.

* * * * *

ELECTRICAL STANDARDS.

_Nature_ states that the Queen's Printers are now issuing the Report
(dated July 23, 1891) to the President of the Board of Trade, of the
Committee appointed to consider the question of constructing standards
for the measurement of electricity. The committee included Mr.
Courtenay Boyle, C.B., Major P. Cardew, R.E., Mr. E. Graves, Mr. W.H.
Preece, F.R.S., Sir W. Thomson, F.R.S., Lord Rayleigh, F.R.S., Prof.
G. Carey Foster, F.R.S., Mr. R.T. Glazebrook, F.R. S., Dr. John
Hopkinson, F.R.S., Prof. W.E. Ayrton, F.R.S.

In response to an invitation, the following gentlemen attended and
gave evidence: On behalf of the Association of Chambers of Commerce,
Mr. Thomas Parker and Mr. Hugh Erat Harrison; on behalf of the London
Council, Prof. Silvanus Thompson; on behalf of the London Chamber of
Commerce, Mr. R. E. Crompton. The Committee were indebted to Dr. J.A.
Fleming and Dr. A. Muirhead for valuable information and assistance;
and they state that they had the advantage of the experience and
advice of Mr. H. J. Chaney, the Superintendent of Weights and
Measures. The Secretary to the Committee was Sir T.W. P. Blomefield,
Bart.

The following are the resolutions of the Committee:

_Resolutions._

(1) That it is desirable that new denominations of standards for the
measurement of electricity should be made and approved by Her Majesty
in Council as Board of Trade standards.

(2) That the magnitudes of these standards should be determined on the
electro-magnetic system of measurement with reference to the
centimeter as unit of length, the gramme as unit of mass, and the
second as unit of time, and that by the terms centimeter and gramme
are meant the standards of those denomi