Proceedings of the British Association. 115 



their diurnal and annual oscillations. At Toronto the degree of 

 humidity was greatest at the coldest hour of the day, and least at the 

 hottest with remarkable regularity, the curve of humidity harmoniz- 

 ing with that of temperature, but being inverted in its range. The 

 average state of the air at Toronto was that it contained 0*78 parts 

 of the moisture required for its saturation. The curve of mean ten- 

 sion of the vapour had an ascending and descending branch, in exact 

 harmony with that of temperature. He then pointed out some re- 

 markable deviations from this agreement, and particularized the 

 climate of Trevandrum, in the East Indies. After examining the 

 mean monthly humidity and tension, he proceeded to consider the 

 atmospheric pressure, and compared the barometrical ranges at 

 Toronto and Prague, and showed how remarkably similar were the 

 phenomena which presented themselves in this subject over the 

 two continents ; and noticed a case in which, at each place, within 

 the compass of a very few days, the highest and the lowest observed 

 height of that instrument occurred, being apparently part of one 

 great atmospheric wave. Col. Sabine strongly recommended that 

 hygrometric observations should always accompany those of the baro- 

 meter ; and that reductions should be made and registered at the 

 time, otherwise unreduced observations would be so unaccountable 

 as to become worthless. 



A discussion followed, chiefly upon the theoretic views adopted by 

 Col. Sabine, all the speakers concurring in the value of the observa- 

 tions, and the skill and ability displayed in their discussion. 



■ On a new process of Magnetic Manipulation, and its action on 

 cast iron and steel bars/ by the Rev. Dr. Scoresby. Dr. Scoresby 

 found that it was impossible, by the ordinary process, to commu- 

 nicate the full charge of magnetic influence to very hard shear-steel 

 or cast steel bars, or such as were best suited for retaining it, and 

 therefore best for the manufacture of compasses. But he was led, by 

 the theoretic views he holds, to try the effect of interposing thin bars 

 of soft iron between the charging poles of the magnet, and the steel 

 bar to be magnetized : this answered effectually and Dr. Scoresby 

 exhibited to the section several experiments, whereby, with the old 

 process, the magnetism imparted to the steel bars was very trivial, 





