XXIV 



name most indissolubly with the science of the nineteenth century is 

 to be found in the subject of terrestrial magnetism. It is here that 

 his labours, whether conducted singly or in association with other 

 investigators, have left the most permanent mark ; and it is not too 

 much to say that no single individual contributed more largely to the 

 success of the effort which was made to perfect by observation our 

 knowledge of the earth's magnetic force. 



At the first meeting of the British Association in 1831, the Com- 

 mittee of Section A reported that it was highly desirable that a 

 series of observations upon the intensity of terrestrial magnetism in 

 various parts of England be made by some competent individual, 

 similar to those which had been recently carried on in Scotland by 

 Mr. Dunlop. In compliance with this suggestion r some experiments 

 were made in the neighbourhood of Liverpool, by W. S. Traill, M.D., 

 the results of which were laid before the Association in 1832. In 

 1833 the Committee extended their recommendation so as to include 

 the whole kingdom, appointing as a Standing Committee, charged 

 with the promotion of these objects, Professors Christie, Forbes, and 

 Lloyd. At the same time Dr. Lloyd undertook to make the required 

 observations in Ireland. These observations were carried on in the 

 year 1834 by Dr. Lloyd, with the assistance of Captain (afterwards 

 Sir Edward) Sabine, and subsequently of Captain (afterwards Sir 

 James) Ross. A brief communication on the method of these 

 observations was made by Dr. Lloyd to the Association in 1834. In 

 this communication he described a new method of obtaining the 

 values of the intensity and the dip, by observation of a magnet 

 turning round a horizontal axis. This method had been previously 

 communicated to the Royal Irish Academy by Dr. Lloyd (October, 

 1833) and is published in the seventeenth volume of their " Trans- 

 actions." A full report of observations made at. twenty-four stations 

 in various parts of Ireland was laid before the British Association in 

 1835, and is published, along with a magnetic chart of Ireland, in the 

 Report for that year. This was followed, in 1838, by an elaborate 

 memoir, " On the Magnetic Survey of Great Britain," from the pen 

 of Major Sabine, embodying the results of observations made by 

 several distinguished physicists, including Dr. Lloyd. 



In the same year the Association came to the conclusion that a 

 wider scope ought to be given to the inquiry, by establishing stations 

 for simultaneous magnetic observations in various parts of the world. 

 As it was impossible for private individuals to carry out so extensive 

 a plan, it was resolved to endeavour to obtain the co-operation of the 

 Government, and a Committee, consisting of Sir J. Herschel, 

 Dr. Whewell, Mr. Peacock, and Dr. Lloyd, was appointed for this 

 purpose. The representations made by this Committee, strongly 

 backed by the Royal Society, were successful, and Magnetic Observa 



