431 



Fourteenth Meeting of the British Association for the Advancement of 



Science. York: September 28th, 1844, 



(Concluded from page 293.) 



Section A.— MATHEMATICAL AND PHYSICAL SCIENCE. 



The discussion of the difference of opinion between Prof. Forbes and 

 Mr. Hopkins, as to the mechanism of the motion of Glaciers was resum- 

 ed, and occupied three hours. As the views of the parties have been for 

 some time before the public, we need not further enter on the subject. 



1 On the Geodetical Operations of India,' by Lieut.-Col. Everest, late 

 Surveyor-General of India. — A series of triangulations, on the most 

 magnificent scale, has for many years been conducted in India, by Col. 

 Lambton up to the year 1823, and after his death, by Col. Everest (who 

 had, for some years previous, been his chief assistant) up to the close 

 of 1843, when this officer resigned the charge to Capt. Waugh, of the 

 Bengal Engineers. As the Court of Directors of the East India Company 

 have directed the publication of Col. Everest's labours, it is unnecessary 

 to enter into the important details laid before the Section. It is to be 

 regretted that the series of triangles and several others which are de- 

 scribed in Col. Everest's paper, have not been filled up by any secondary 

 triangulation, or made available to any of those social purposes to which 

 accurate district maps are so important. In Colonel Everest's conclud- 

 ing words, " It is to be hoped that the powers who govern India will 

 see the necessity of taking early measures to cause all these series to be 

 filled up with topographical details, in keeping as to accuracy with the 

 material now on record. At present, the principal triangles are, in 

 many places, mere skeletons, instruments of mighty power lying use- 

 less. But it seems very clear, that without accurate and specific detail, 

 whether as relates to topographical or statistical knowledge, no state can 

 be well governed ; and the maps in the possession of the governing power 

 ought, for this purpose, to lie within certain and decided limits of error." 



Col. Everest also described an instrument, called a Barometer Pump, 

 for filling barometer tubes in vacuo. This was a single acting air-pump, 

 so arranged as to exhaust the air from the tube to be filled, while a 

 capillary tube, dipping into a reservoir of mercury, and curved at the end 

 next the tube, dropped the mercury into the tube as it rose above the 

 bend, (after the exhaustion had been carried as far as possible), by dip- 

 ping a glass rod into the reservoir. The mercury as it comes into the 

 tube is heated to a temperature sufficient to boil it, and it is desiccated 

 by a bottle of strong sulphuric acid, which is made to communicate with 

 the canal into which the tube to be filled and the capillary filling tube 



