44 BEPOET — 1889. 



must be multiplied to give the effective electromotive force. Thus, in the 

 case of a circuit of resistance R ohms, and self-induction L quadrants, in 

 which a simple harmonic electromotive force of frequency, nj 2-77, is acting, 

 Impedance = a/ [R^ + 1? «^} . 



(11) In an Accumulator the positive pole is that which is connected 

 with the positive pole of the machine when charging, and from which 

 the current passes into the external circuit when discharging. 



Of the lOOZ. voted to the Committee last year, Ihl. has been drawn from 

 the treasurer; 60^. towards defraying the cost of the air-condensers, and 

 15/. for some resistance coils and thermometers required for testing. 



The Committee are of opinion that they should be reappointed, with 

 the addition of the name of Prof. J. Viriamu Jones, and with a grant of 

 50Z. to continue the experiments which are now in progress. 



They propose that Prof. G. Carey Foster should be the Chairman and 

 Mr. R. T. Glazebrook the Secretary. 



Second Report of the Committee, consisting of the Hon. Ralph 

 Abercromby, Dr. A. Buchan, Mr. J. Y. Buchanan, Mr. J. 

 Willis Bund, Professor Chrystal, Mr. D. Cunningham, Pro- 

 fessor Fitzgerald, Dr. H. R. Mill (Secretary), Dr. John 

 Murray {Chairman), Mr. Isaac Roberts, Dr. H. C. Sorby, 

 and the Rev. C. J. Steward, appointed to arrange an 

 investigation of the Seasonal Variations of Temperature in 

 Lakes, Rivers, and Estuaries in various parts of the United 

 Kingdom in co-operation luith the local societies represented on 

 the Association. 



No formal meeting of the Committee has been held, but some of the 

 members have occasionally met informally, and the whole Committee has 

 been consulted by letter on all the arrangements which have been com- 

 pleted. It is inadvisable to attempt at present to summarise the results of 

 observations made, as, although more than a year's observations are avail- 

 able on some rivers, it is only a few months since the work has been begun 

 on others. At the end of another year it is expected that sufficient data 

 will be found to justify a comprehensive report on the subject. 



Several members of the Committee have taken much trouble in 

 collecting observations. Dr. Sorby has been good enough to collect and 

 discuss a great mass of temperature observations which he had made from 

 his yacht Glimjpse, in the estuaries of the south-east of England during 

 the summer months of five successive years. This will be published 

 separately. Professor Fitzgerald took charge of the observations in 

 Ireland, where he induced a number of observers to take up the work. Mr. 

 Willis Bund had already inaugurated similar researches on the Severn. 

 Rev. C. J. Steward and Mr. Isaac Roberts rendered important services in 

 their districts. 



A circular was sent to all the Corresponding Societies in connection 

 ■with the Association, requesting their co-operation, and favourable replies 

 were received from several, intimating that observations had been com- 

 menced. 



Many observers came forward in response to a letter in the newspapers, 



