TRANSACTIONS OF THE SECTIONS. 17 



read off, and a table prepared beforehand supplies the corresponding resistance in 

 units. In this way, during the paying out of a cable, the state of the line can at 

 any time be known without expending time in calculating the observations. 



On some New Arrangements of the Poles of Magnets. By Capt. Selwtn. 



The author described a method by which magnets may be made of which botli 

 ends possess north polarity or south polarity at will ; aud under these circumstances 

 the place of both the south or both the north poles will be found in close juxtapo- 

 sition in the centre of the bar. The process by which these effects are produced 

 is to take out the temper of the bar, at any point where it is desired the two poles 

 shall be in proximity, by a rod of heated metal or by the blowpipe. This opera- 

 tion, while seemingly leaving the bar intact, has separated the two magnets, 

 though the ends will still be respectively north and south poles. If now the north 

 pole of a strong magnet be used and drawn from the centre of the bar towards the 

 north end of the prepared needle, the polarity of that half will be reversed without 

 affecting the other end, and by a series of careful touches both ends will become 

 equally balanced south poles, as in a specimen exhibited to the Section. If the bar 

 has been softened in more than one place, a series of magnets may be produced in 

 the same piece of steel with similar or dissimilar poles in juxtaposition. 



Capt. Selwyn also exhibited and described to the Section a new form of horizontal 

 galvanometer, compensated by the introduction of a natural fixed magnet, in addi- 

 tion to the moveable one which is deflected by the current of electricity in these 

 instruments. This is kept at zero by the attraction of the first, and its force is 

 exerted in opposition to that of the current of electricity, and in a similar ratio. 



Meteorology. 



Remarks upon Aerial Navigation, suggested by Mr. Glaisher's late Balloon 



Ascents. By F. W. Brearey. 



Mr. Brearey, alluding to the important observations of Mr. Glaisher, remarked 

 that he had only been creeping along the borders of a vast immensity of which we 

 know almost nothing. 



Now that public attention was directed to these scientific efforts, and that the 

 balloon was becoming more than a toy, he would at once propose the formation of 

 a society, to be supported by subscriptions and donations, by which experiments 

 could be conducted in its own grounds, and with its own apparatus, for the further- 

 ance of investigations in aerology and aerial locomotion. 



After pointing out the requirements of aeronauts for locomotive purposes, 

 Mr. Brearey suggested, with the object of saving gas and ballast, that a man might 

 raise himself iu the air by a mechanical appliance attached to a balloon inflated only 

 to such an extent as woidd give him buoyancy. The downward blow of paddles 

 made of bamboo and silk, if returning feathered for each succeeding stroke, would 

 enable him to effect this, and also to keep a low elevation, go with the wind, 

 ascend and descend at pleasure, find different currents, and save his gas for future 

 use. 



It would, moreover, comply with the conditions insisted upon by late writers on 

 aeronautics, viz. " that, to contend with the air, one must be specifically heavier 

 than the air." 



On the Great Storm of December 1864, on the Coast of the Peninsula. 



By J. B. Capello. 



On the Heat attained by the Moon under Solar Radiation. 

 By J. Park Harrison, M.A. 

 On the assumption that the moon's crust is constituted geologically like the earth, 

 1865. 2 



