82 REPORTS ON THE STATE OF SCIENCE. 



times that rate. Because the paper is on a cylinder and not used as a 

 band, about half the quantity of fiim is employed, an open scale is 

 obtained, and in many cases, owing to the absence of halation due to 

 long exposure, the Hhide Registers, as published by the British Asso- 

 ciation, show that earlier commencements are obtained. With the 

 present receiver, it is distinctly the most satisfactory instrument with 

 which I have had any experience. Its value as a recorder of minute 

 tremors is indicated on p. 64. For a description of the instrument see 

 British Association Report, 1904, p. 44. 



X. Map of the World. By R. D. Oldham. 



Tfte accompanying map of the world, Plate III., was made by Mr. 

 R. D. Oldham for certain purposes of his own, but as it was thought 

 it night be of general use to seismologists we have, with his consent, 

 added it to this report. Mr. Oldham describes the map as follows : — 



'The map is constructed on the zenithal projection, with Greenwich 

 as the centre. All great circles passing through the centre of the map 

 are n-presented by straight lines, and equal distances measured along 

 these great circles on the surface of the earth by equal radial distances 

 on the map. Meridians and parallels of longitude and latitude are 

 drawn at intervals of 15°, and intervals between the concentric circles 

 represent intervals of 15° of arc, or an average linear distance of 900 

 nautical miles, or 1,G67 kilometres. Fur convenience, and to avoid 

 excessive distortion, the wliole surface of the earth is divided into two 

 hemispheres ; in the one, distances are to be measured directly from the 

 centre outwards, in the other they are measured from the circumference 

 inwards, and added to the length of the radius of the map. This 

 represents one quarter of the circumference of the globe. The direction 

 of the straight line drawn from any point to the centre of the map 

 gives the azimuth of the great circle at Greenwich. The map may also be 

 used for obtaining the distance between any two points situated on tlie 

 same great circle with each other and Greenwich, but cannot be used 

 with accuracy for measurements between two points not so situated. 



' Though constructed to Greenwich as a centre, it can be used with 

 sufficient accuracy for many purposes for any place in the British Isles 

 or the nearer parts of Europe.' 



XI. A Catalogue of Chinese Earthquakes. .B^ Suinobu Hirota. 



In May 1839 Ed. Biot presented to the Academie des Sciences a 

 ' Catalogue General des tremblements de tcrre, atiaissements et soulcve- 

 ments de montagnes, observes en Chine depuis le tenips anciens jusqu'a 

 nos jours.' This was published in the ' Annales de Chiuiie et de Physique,' 

 tome ii. 18-il, p. 372. Ic contains references to about 480 earthquakes. 

 In the twenty-ninth volume of the Reportsof the Imperial Earthquake 

 Investigation Committee, 1899, Dr. F. Omori gives a Catalogue of 

 Chinese Earthquakes. It is printed in Chinese ideographs, and the 

 characters he uses are apparentjy those in the works from which he 

 quotes. Both M. Biot and Dr. Omori quote from the Chinese author 

 Matouanlin, who made a catalogue of earthquakes and the historical 

 annals called Thoung-kien-khang-mou. Dr. Omori has also referred to 

 other Chinese histories. By combining these two catalogues one result 

 is that the 480 entries in M. Blot's catalogue is now extended to 889, 



