TRANSACTIONS OF THE SECTIONS. 9 



ference to the standing orders of Parliament in railway matters, &c.) in introducing 

 the measure of 1000 yards, which might be called a milyard. However, the commis- 

 sion made no recommendations as to nomenclature, leaving that to the legislature. 

 Thus the changes proposed to be introduced, not only to ensure a decimal coinage, 

 but a decimal subdivision of weights and measures, were by no means of that formi- 

 dable and appalling character which many persons suppose they must of necessity 

 possess. 



Letter from Professor Wlieatstone to Colonel Sabine, on a New Meteorologi- 

 cal Instrument. 

 The importance of multiplying stations at which simultaneous meteorological obser- 

 vations may be made does not require any discussion. The chief obstacle to their 

 establishment is the necessity for the constant attendance of an observer to register 

 the indications of the instruments, which difficulty is greatly increased when the ob- 

 servations are required to be made by night as well as by day. All attempts to make 

 self-recording thermometers, barometers, &c. by mechanical means have hitherto 

 failed, because the mechanical force exerted by the rise of the mercury in the tubes is 

 insufficient to overcome the frictions of the attached mechanism, and only very inac- 

 curate indications can be obtained. The principle, however, which I employ in my 

 meteorological telegraph, viz. the determination (by means of a feeble electric current) 

 of any required mechanical force by the mere contact of the mercury in the tube with 

 a fine platina wire, enables all these difficulties to be overcome, and a Meteorological 

 Recorder may now be made, which shall register every half hour the varying indi- 

 cations of the barometer, thermometer and psychrometer, as accurately as the most 

 careful observer would be able to do, and which will require only a few minutes at- 

 tention each day to put it in proper order to act for twenty-four hours. I propose 

 therefore that such an instrument, the cost of which I estimate will not exceed 50/., 

 shall be constructed, under my direction, for the Richmond Observatory. If, after a 

 few months' trial at the Observatory, it shall be found to succeed, as I confidently ex- 

 pect it will, a great impediment to the advancement of meteorological science will be 

 removed. Persons in almost every locality may be found who would not object to de- 

 vote a few minutes per day to prepare such an instrument for use, but who would 

 find it impossible to give the requisite attention to make hourly or half-hourly obser- 

 vations themselves ; and the cost of the apparatus (which may hereafter probably be 

 considerably reduced) is, considering the important objects in view, too inconsiderable 

 to stand in the way of its general adoption. 



On the Application of the Principle of the Vernier to the Subdividing of 

 Time. By Follet Osler. 



Mr. Osier's idea was, to have a pendulum, which should make, say ten swings in 

 the time that the principal pendulum made eleven, furnished with a small dial, and so 

 placed as that the coincidences, or want of coincidence, could be observed. The strokes 

 of such a pendulum being counted, the time of every observed stroke of it, reckoned 

 back from its coincidence with the principal, or seconds pendulum, would, it is ob- 

 vious, be found in tenths of a second. 



On the Longitude of Devonport. By E. J. Dent. 

 Longitude of the landing-place on the Breakwater in Plymouth Sound , u 



by four chronometers 16 33 - G0 west 



Longitude of staff on Mount Wise by Trigonometrical Survey 16 38-10 



The same, by mean of four chronometers 16 39-80 



Difference 170 



On the Rate of Protected Chronometer Springs. By E. J. Dent. 



The author stated, that by trial at the Royal Observatory, Greenwich, between the 



