BRITISH ASSOCIATION FOR THE ADVANCEMENT 



OF SCIENCE. 



Life Members (since 1845), and all Annual Members who have not 

 intermitted their Subscription, receive gratis all Reports published after 

 the date of their Membership. Any other volume they require may be 

 obtained on application at the Office of the Association, Burlington 

 House, Piccadilly, London, W., at the following prices, viz.— Reports for 

 1831 to 1874 {of which more than 15 co]^ies remain), at 2s. 6d. per volume ; 

 after that date, at two-thirds of the Publication Price. A few sets, from 

 1831 to 1874 inclusive, may also be obtained at £10 per set. 



Assuciates for the Meeting in 1901 may obtain the Volume for the Year at two-thirds 



of the Publication Price. 



REPORT OP THE SEVENTIETH MEETING, at Bradford, 

 September, 1900, Published at £1 is. 



CONTENTS. 



Kules of the Association, Lists of Officers, Keport of the Council, List of Com- 

 mittees, Grants of Money, &c xxvii-cxvi 



Address by the President, Sir William Turner ..'.'.'.'!. 3 

 Report on the Establishment of a Meteorological Observatory at Montreal . 33 

 Report on the present State of our Knowledge in Electrolysis and Electro- 

 chemistry ••.......,... 34 



Report on the best methods of recording the Direct Intensity of Solar 



Radiation . •■•......... 36 



Report on the Desirability of securing Uniformity of Size of Pages of 



Transactions ............. 45 



Report on the most suitable Method of determining the Components of the 



Magnetic Force on Board Ship 45 



Report on the Calculation of certain Mathematical Functions .... 46 



Report on Meteorological Observations on Ben Nevis 46 



Report on Radiation in a Magnetic Field 52 



Report on Electrical Standards .......... 5S 



Tenth Report on Photographic Meteorology .' ! 56 



Fifth Report on Seismological Investigations 59 



Report on the present State of the Theory of Point-groups. Part I. By 



Frances Hakdl'Astle . . . ' 121 



