4^ Analyses of BooJis. [Dec. 



which was soldered to a copper rod which served as a conducting 

 continuation of the wire : 2nd, as an ordinary helix formed of a 

 copper wire coiled round a pasteboard tube, the convolutions being 

 separated by a string, and the superposed helices prevented from touch- 

 ing by intervening calico : 3rd, as a long extended wire, and 4th, as a 

 short wire. Of all these forms, the brightest spark and most powerful 

 shock are procured by inserting a cylinder of soft iron within the helix, 

 so as to form an electro-magnet. He found, also, that if a current 

 be established in a wire, and another wire forming a complete current 

 be placed parallel to the first, at the moment the current in the first 

 is stopped, it induces a current in the same direction in the second, 

 the first exhibiting then but a feeble spark ; but, if the second wire 

 be removed, a current is induced in the first wire in the same direction, 

 and a spark elicited when the contact is broken. The strong spark 

 in the single long wire or helix, is therefore, the equivalent of the 

 current which is induced in a second wire placed parallel and in 

 connexion with the first wire. From the facility of transference to 

 neighbouring wires, and from effects generally, he considers the 

 inductive forces to be lateral, i. e. excited in a direction perpendicular 

 to the direction of the originating and produced current, and they 

 also appear to be accurately represented by the magnetic curves, and 

 closely related to, if not identical with magnetic forces. All experi- 

 ments tend to shew that the elements of the currents do not act upon 

 themselves, but excite currents in conducting matter which is lateral 

 to them. On using a voltaic battery with fifty pairs of plates the 

 effects were exactly similar to those with a single pair. The author 

 concludes with remarking upon the advantages presented by electro- 

 magnetic machines, in which the current is permitted to move in a 

 complete metallic circuit of great length during the first instant of its 

 formation, by which means great intensity is given by induction to 

 the electricity which at that moment passes. 



On the Determination of the Terms in the Disturbing Function, 

 of the Fourth Order, as regards the Eccentricities and Inclinations 

 which give rise to Secular Inequalities. By J. W. Lubbock. 



In the theory of the secular inequalities, the terms in the disturbing 

 function of the fourth order, as regards the inclinations, have hitherto 

 been neglected. As the magnitude of these terms depends, in a great 

 measure, upon certain numerical co-efficients, it is impossible to form 

 any precise notion, a priori, with respect to their amount, and as to 

 the error which may arise from neglecting them. The author has, 

 therefore, considered it desirable to ascertain their analytical expres- 

 sions. The details of this calculation form the subject of this paper. 



On the Results of Tide Observations made in June 1834, at the 

 Coast Guard Stations in Great Britain and Ireland. By the Rev. 

 W. Whewell. 



This paper consists of a statement of certain deductions which the 

 author draws from such of the registered tidal observations as have 

 been reduced ; by correcting the times, as far as the methods em- 

 ployed would allow, and subtracting from each time of tide, tlie 



