372 Proceedings of the British Association. 



tions upon a large scale, which are dependent upon the weather, 

 have been frequently and successfully conducted in accordance with 

 these rules. He considered the severe frost of 1813-14, which 

 continued about twelve weeks, with partial thaws intervening, and 

 the severe weather of succeeding winters, with their intermissions, 

 to be closely connected with the above rules. The partial rains also 

 of very dry summers have been found to take place at the same 

 seasons of change, insomuch that for amusement he had frequently 

 traced back the periods connected with the age of the moon, from 

 the thaws that took place in severe weather, or the rains occurring 

 in long continued drought. Residing on the banks of the river, and 

 taking much interest in the operations of Professor Whewell respect- 

 ing the tides, and his description of these, Mr, Hall stated that he 

 had been led closely to compare them with the weather; but diffi- 

 culties to him insurmountable had occurred, when considering the 

 variations of weather in different places at the same time ; yet, re- 

 garding those in the neighborhood of Bristol, his conviction was 

 unwavering. Perhaps the varying time at which the tide reaches 

 various places, so fully described by Professor Whewell in his lec- 

 ture on Tuesday evening, might assist in solving this difficulty ; and 

 if the attention of others were directed towards it, his end would be 

 attained. 



Mr. Ettricke then gave a description of "an instrument intended 

 to observe minute changes of Terrestrial Magnetism," and of other 

 philosophical instruments. 



Mr. R. Addams then made a communication respecting the vibra- 

 tion of bells. 



Mr. Rootsey then read papers "on the Music of the Greeks, and 

 a systein of Mnemonic Logarithms." 



Section B, — Chemistry and Mineralogy. 



Dr. Daubeny stated, that he had ascertained that the sublimation 

 of carbonate of magnesia was entirely a mechanical process, and he 

 inferred that no support could hence be given to Von Buch's well 

 known theory of dolomization. 



Dr. Dalton then gave an exposition of his views upon the subject 

 of chemical notation, and the atomic constitution of chemical sub- 

 stances. 



Mr. Johnston explained the use of some chemical tables which 

 he exhibited. 



