\/A' //'//./././.I/ .s/A.l/A.Y.s, /-'.A'-.s. 377 



highest opinion of the conscientious care peculiar to the observer ; 

 but no such cause could possibly have operated regarding the 

 ol.srrvalions of the instrument recorded in the series of observa- 

 tions given in the second Table, when the vessel passed through 

 seas which had not been before sounded, but which were sounded 

 a ft i T each observation of the instrument had been made. 



I n this Table, p. 876, columns 1 and 2 contain the dates and 

 hours observations were made ; ;} and 4, the latitude and longitude 

 of the locality when ascertained ; f>, the indications of the thermo- 

 meter ; 6, the indications of the barometer ; 7, the indications of 

 the bathometer ; 8, the corrections for variations in temperature 

 and atmospheric density ; 9, the readings of the bathometer so 

 corrected; 10, the soundings taken; 11, the difference of these 

 and the bathometer indications. The soundings were made by 

 means of Sir William Thomson's steel-wire sounding-apparatus, 

 lY which admirable improvement over the old sounding-line 

 it is now possible to take soundings exceeding 2,000 fathoms 

 in an hour, when 5 or 6 "hours were formerly required, and 

 by the application of mechanical power to recover the steel win? 

 itself in from 15 to 20 minutes when a detaching weight is 

 employed. 



The reading of the bathometer was in each case reported to 

 Captain Trot, of the steamship " Faraday," before the sounding- 

 line had reached the bottom ; and the fair accordance between 

 the results obtained by sounding and those given by the instru- 

 ment furnishes ample proof of the reliable nature of the batho- 

 meter indications. The series of observations was unfortunately 

 inteiTUpted during the homeward voyage by a heavy gale, whereby 

 the instrument was exposed to splashes of sea-water from the 

 deck ; it had to be taken down, and was only remounted when 

 the vessel had arrived at the Victoria Docks. It will be observed 

 that the readings taken in the Victoria Docks, before and after 

 the voyage, agree, after allowing for difference of temperature and 

 atmospheric density, within 5 divisions on the scale of the instru- 

 ment, representing 5 fathoms of depth, an accordance which must 

 be considered highly satisfactory. 



INFLUENCE OF ELEVATION ABOVE THE EARTH'S SURFACE. 

 The bathometer is applicable also to the measurement of height, 

 for which purpose it possesses the advantage over the aneroid 



