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 denominations deposited with the Board of Trade. (3) That the standard of electrical resistance should be denominated the ohm, and should have the value 1,000,000,000 in terms of the centimeter and second. (4) That the resistance offered to an unvarying electric current by a column of mercury of a constant cross sectional area of 1 square millimeter, and of a length of 106.3 centimeters at the temperature of melting ice may be adopted as 1 ohm. (5) That the value of the standard of resistance constructed by a committee of the British Association for the Advancement of Science in the years 1863 and 1864, and known as the British Association unit, may be taken as 0.9866 of the ohm. (6) That a material standard, constructed in solid metal, and verified by comparison with the British Association unit, should be adopted as the standard ohm.