Jan. 2, 1890] 



NA TURE 



203 



evidence of modern compilations furnishes the testimony 

 that as many as six or eight minor shocks have occurred 

 annually in recent years. In evidence of the prevalence of 

 such phenomena in England, it should be also remem- 

 bered that it was on this island that Prof. George Darwin 

 first discovered the fact of the continuous microseismic 

 vibration of the earth's crust. 



The new edition of the late Mr. William Roper's excel- 

 lent summary of the principal earthquakes that have 

 been recorded in Great Britain and Ireland during this 

 era, which has lately been issued/ bears witness both 

 to the frequency of such phenomena, and, even more 

 strikingly, to the great advance that has taken place within 

 recent years in the study of seismology in Britain. The 

 increased attention which has been devoted to the subject 

 is doubtless partly due to the extensive shock which 

 occurred in this country in 1884. 



The famous Catalogue compiled by Robert Mallet will 

 ever remain the cyclopaedic work of reference upon which 

 all subsequent earthquake catalogues will necessarily be 

 based ; and the name of Mallet, as the authority, naturally 

 figures most extensively in Mr. Roper's list. Until re- 

 cently, it may, indeed, be said that the work of Mallet, 

 and of M, Alexis Perrey, of Dijon, stood almost alone 

 as the historical register of seismic force in the world. 

 Within the last few years, however, the valuable experi- 

 mental work of Prof. Milne and others in Japan, and of 

 numerous European and American seismologists, has 

 been supplemented by several treatises devoted to British 

 earthquakes alone. Some of these publications — as the 

 detailed report of the great Essex earthquake, and Mr. 



E. Parfitt's Devonshire Catalogue— being issued in con- 

 nection with particular areas, and by local scientific 

 bodies, have had a restricted application ; whilst others, 

 as Prof. O'Reilly's catalogue, and the one just mentioned, 

 have included the entire British Islands in their scope. 

 It was the intention of the present writer, when engaged, 

 in conjunction with Prof. Meldola, upon the Report of the 

 East Anglian earthquake,''^ to furnish a full list of British 

 earthquakes ; but, from the quantity of material accumu- 

 lated from very many sources, it was found that so ex- 

 tensive a catalogue grew entirely out of proportion to 

 the purpose of a special monograph, and only those 

 disturbances which had similarly caused structural 

 damage were included in that memoir. These alone, 

 however, number as many as sixty well-authenticated 

 records, although Mr. Roper, in his catalogue, which, 

 unfortunately, is very scanty in point of detail, omits fully 

 25 per cent, of these injurious shocks. But since his 

 catalogue too modestly professes to include only "the 

 more remarkable earthquakes," it is to be expected that 

 numerous omissions might be noticed, and we could 

 readily add to his list over two or three dozen records 

 (both mediaeval and modern) which fully equalled the 

 average intensity of those he has included. In fact, 

 while it may be said to form the most comprehensive 

 list of British earthquakes that has yet been produced, 

 it is incomplete, and it is much to be regretted that 

 the compiler did not survive to finish his erudite 

 undertaking, as is explained in a prefatory note by 

 his son. 



Mr. Roper has, in effect, unconsciously erred unduly 

 on the side of moderation, since he includes most of the 

 fabulous stories that belong to mediaeval times, while he 

 has omitted many important shocks. This recalls a 

 somewhat strange incident in connection with the 1884 

 earthquake — namely, that more damage actually occurred 

 in the out-of-the-way villages chiefly affected by the shock, 

 than was ever reported in the London newspapers — a 



" A List of the more Remarkable Earthquakes in Great liritain and 

 Ireland diinng the Christian Era." Compiled by William Roper, F.S.S., 



F. R.Met.Soc. (Lancaster: Thos. Bell.) 



^ "Report on the East Anglian Earthquake of April 22, 1884." By 

 R.-iphael Meldola, F.R.S., &c., and William White. (Essex Field Club 

 Special Memoirs, vol. i.) (London : Macmillan and Co., 1885.) 



fact which does credit to the caution exercised by 

 the daily press writers at the time. Too much, on the 

 other hand, was made of the really slight but widely dis- 

 tributed shock which took place on May 30 in the present 

 year, when no displacement of furniture nor stoppage of 

 clocks then resulted ; the experience being limited to the 

 rattling of windows and the swaying of walls, as may be 

 seen on referring to the summary which appeared in 

 Nature for June 6 (pp. 140-42). 



Covering so considerable a period of history, and in- 

 cluding so much subject-matter, Mr. Roper's work cer- 

 tainly deserved a more extended treatment than it has 

 received. An introductory analytical chapter would 

 have added considerably to the interest of such a cata- 

 logue, while a fuller elaboration and thorough editing 

 would have advantageously extended the work beyond 

 its unpretentious limit of fifty pages. The convenient 

 method adopted by Mr. Roper of inserting a preliminary 

 list of " principal authorities cited," is almost compulsory 

 in such a work, for the purpose of establishing a code of 

 abbreviations for subsequent use in the columns of the 

 list ; but the titles are generally given imperfectly or in- 

 correctly, without the requisite details of publication, 

 while the dates, where given, are not throughout those 

 of the original, as they should be, but of later reprints. 

 These and similar slight defects are inconvenient in an 

 historical treatise, and we hope they may receive attention 

 in the event of another edition of this interesting list being 

 called for. 



The total number of distinct earthquakes included in 

 this catalogue— regarding the series of repeated shocks 

 which sometimes take place within a brief period as a 

 single record — amounts to 582, and an analysis of these 

 records may be of interest here, as furnishing some slight 

 indication of the chronological distribution of the chief 

 seismic disturbances which have been accounted in 

 British annals as having taken place within our area. 

 They may, for convenience, be arranged as they occurred 

 during each century, and term of 500 years : thus — 



'^ Total during the ist 500 years 34 



„ . „ 2nd „ 28 



3rd ,, 97 



4th „ 423 



It may perhaps be fairly assumed from this table that 

 no true estimate of the actual number of shocks happen- 

 ing within each period can be arrived at, for the chief 

 reason that the records are entirely subject to the irre- 

 gularities of the few capable observers of the early cen- 

 turies. It is to be observed that 423 shocks, or nearly 

 75 per cent, of the total number, have occurred since 

 1600, which may be considered as the period from which 

 the more trustworthy accounts commenced. There is no 

 reason whatever for supposing that the frequency of 

 seismic shocks has increased since that period ; and the 

 evidence indicates little more than the activity of the 

 observers, who appear to have fallen off considerably at 

 times, as during the fourteenth and fifteenth centuries. 

 This point is worth remarking, on account of the mis- 

 leading statement that has been more than once made, 



