TRANSACTIONS OF THE SECTIONS. 19 



On the Positive and the Negative Streams of Electrified Air, and on an 

 Electrical Machine fitted for examining them. By the Rev. C.J. Kennedy. 



On Improved Magnets, and the different Modes of determining their Powers, 

 with an Account of certain undescribed Phcenomena in Permanent Mag- 

 netics. By the Rev. W. Scoresby, D.D.' F.R.S., §c. 



The author having called attention to the varying relations of capacity for, and 

 retention of, the magnetic condition in specimens of steel of different mass, hardness, 

 and quality, showed by experiments with compound magnets, constructed by himself 

 after an extended investigation of their relations, the possibility of communicating 

 and retaining very unusual magnetic energy in systems of bars, suited for various 

 practical purposes. A magnet exhibited was stated to be of nearly ten times the power 

 of one on the ordinary principle of equal mass. The phsenomena exhibited by it 

 were, indeed, very striking, particularly its capability of suspending above 10,000 

 small nails in a loop which could be moulded like plastic clay. 



In respect to the different methods of determining the powers of straight bar mag- 

 nets, Dr. Scoresby showed the superiority in convenience and comparability, of the 

 method of deviations, over that of torsion, and mentioned as a general result, that 

 small bars exhibited greater proportionate magnetic energy than large bars. 



It appeared to have escaped notice that a considerable proportion of the energy of 

 magnets taken in combination existed in a state of elastic sitppression, so that, on se- 

 paration of the bars, a great increase of energy is exhibited in their individual powers. 

 This weakening of some bars placed in contact might even in some cases proceed so 

 far as to give to such bars an opposite magnetic condition whilst in the mass, and 

 thus really diminish the power of the combination. 



The result of his numerous experiments on the subject of the communication and 

 retention of magnetism, was to enable him to show what, for any specific purpose, 

 was the best quality and denomination (as blister-steel, cast-steel, &c.) of steel, and 

 the right degree of hardness. For certain researches concerning the earth's mag- 

 netism, Dr. Scoresby proposed powerful short compound bars (six inches or less in 

 length), of sufficient mass to carry reflecting mirrors for determining minute changes 

 of direction. 



Colonel Sabine read a letter which enclosed Boguslawski's Report ' On the Ob- 

 servations made by him in Breslau with the Magnetic Instruments belonging to the 

 British Association.' 



Supplementary Report of a Committee on Waves. By J. S. Russell, M.A. 



Much of the difficulty experienced in attaining clear conceptions of the phrenomena 

 and mechanism of waves is to be attributed to this circumstance, that we are apt to 

 confound with each other, under the general name of Wave Motion, a variety of phre- 

 nomena essentially different in their origin, their form and their laws. This essential 

 diversity the author of this paper had formerly endeavoured to establish, more espe- 

 cially in the case of that species of wave which he had called the Wave of Transla- 

 tion. In his memoir of observations made in 1 834-35, he had indicated the existence 

 and described some of the phenomena of two other classes of waves, as also in the 

 former printed Reports of the Association ; but he had lately embraced an opportu- 

 nity of extending his observations and maturing a classification, which he now sub- 

 mitted to the Section. 



Of waves, there seem to be three great orders obeying very different laws : — 



(1.) Wave of the First Order. — The wave of translation is solitary, progressive, 

 depending chiefly on the depth of the fluid ; has two species, positive and negative. 



(2.) Waves of the Second Order. — The oscillatory waves are gregarious, the time 

 of oscillation depending on the amplitude of the wave ; of two species, progressive and 

 stationary. 



(3.) The leaves of the third order are capillary waves ; gregarious : the oscilla- 

 tions of the superficial film of a fluid, under the influence of the capillary forces, ex- 

 tending to a very minute depth, short in duration ; of two species, free and constrained. 



The last of these classes he had not before minutely examined, and to them he 



c2 



