178 



NA TURE 



[June 21, 1 906 



persal of mammalian groups, and how profoundly 

 even the present discoveries have modified our con- 

 ceptions of the past history of the mammalia and of 

 the globe in general. 



After a careful study of the volume before us, we 

 have found no occasion for a single word of hostile 

 criticism. The author knows his subject from every 

 possible point of view in a most thorough manner, 

 and has treated it in a thoroughly philosophic 

 way from first to last, while the introduction is 

 written in a style that will appeal to the general 

 reader as well as to the specialist. It is, perhaps, not 

 too much to say that it is the most important con- 

 tribution to mammalian palseontology that has ever 

 appeared within our own recollection on this side 

 of the Atlantic, and if the twentieth century were to 

 see no other work on mammals — either recent or 

 fossil — it would still have a vast achievement to its 

 credit. R. L. 



THE CALIFORNIAN EARTHOUAKE OF 

 APRIL iS. 



^PHE accounts which are reaching this country 



' enable us to form a better idea of the character of 



the Californian earthquake of .^pril t8 last than could 



-The Burnmg of 



be done from the telegraphic reports of the daily 

 papers, and one of the most striking facts which stand 

 out is the wonderfullv small amount of damage done 

 in San Francisco by the earthquake proper. This does 

 not seem to have exceeded the sixth or seventh degree 

 of the Rossi-Forel scale, and the damage to buildings 

 was practically confined to the overthrow of chimneys 

 and of buildings which were either old and badly 

 constructed, or of a design which rendered them 

 especially liable to earthquake damage. The Scien- 

 tifir. American of May 12 contains a view of the busi- 

 ness part of the city, taken after the earthquake, but 

 before the spread of the fire, in which the buildings 

 show little signs of damage, beyond the overthrow of 

 some of the chimney stacks. Where the city was built 

 on made ground settlements and disturbances of 

 ground level led to fractures of the water-mains, but 

 it is not clear from the accounts which have reached 

 us whether there was not also an interruption of the 

 main conduit at some point between the citv and the 

 source of supplv. Whatever the cause, the conse- 



NO. 1QI2. VOL 74] 



quences of the failure of water were disastrous, and 

 the fire, started by the earthquake, was able to spread 

 unchecked. 



Apart from the loss of buildings and lives, San Fran- 

 cisco has lost its most important libraries and scien- 

 tific collections ; the Bancroft library of books and 

 manuscripts relating to the history of the Pacific coast 

 has been saved, as have most of the type-specimens of 

 plants in the collection of the Academy of Sciences, 

 but that is practically all. On the other hand, the Lick 

 Observatory and the University of California have 

 escaped damage, and the working part of the Leland- 

 Stanford University has escaped the complete de- 

 struction which has been the fate of the memorial 

 buildings of that institution. 



The area over which the earthquake did serious 

 damage was confined to a narrow strip of country ex- 

 tending from the town of Ukiah, on the Russian 

 river, to the town of .Salinas, near Monterey Bay. 

 Beyond these limits the country is sparsely settled and 

 may have been vigorously shaken without the fact 

 being reported, but the limits indicated lie about 205 

 miles apart, or 125 miles north and So miles south 

 of San Francisco ; within this strip the damage was 

 very capriciouslv distributed, and died out rapidly to 

 the east and westwards ; at Berkeley town many build- 

 ings were ruined, but the University of California 

 escaped ; San Jose was partly 

 ruined, and most of the buildings 

 of the Stanford University, at Palo 

 Alta, were destroyed, but the Lick 

 Observatory, about fifteen miles to 

 the eastward, was uninjured, nor is 

 any serious injury reported from the 

 (owns on the coast. These peculi- 

 arities in the distribution of the 

 earthquake damage are explained 

 in an article on the probable cause 

 of the San Francisco earthquake by 

 Mr. Frederick Leslie Ransome, pub- 

 lished in the May number of the 

 Xatioiial Geographic Magazine. 

 The article is illustrated by a very 

 clear structural map of the San 

 Francisco peninsula, and an equally 

 clear description of the structural 

 conditions of the region. Probably 

 nowhere in the world have greater 

 displacements taken place in geo- 

 logically recent times than this dis- 

 trict has witnessed ; strata of 

 Quaternary age have here been 

 compressed, contorted, and lifted 

 from 1500 to 2000 feet, and right 

 through the peninsula run three nearly parallel 

 faults, two of which, the Pilarcitos and San Andreas 

 faults, are marked by lines of pools and lakes, 

 proving the recent date of the disturbance to W'hich 

 they owe their origin. The third fault, known as 

 the San Bruno fault, is the most important of the 

 three ; it has a throw of more than 7000 feet near 

 San Francisco, and has been traced, with more or 

 less certainty, from Point Arenas, 100 miles to the 

 north-west, through Southern California, where it 

 is known as the "earthquake crack," almost to the 

 Gulf of California. \ movement along this fault', 

 and others parallel to it, appear to have been the 

 cause of the earthquake, or at any rate of the curious 

 localisation of damage noticed above. The San 

 Bruno fault passes close to the Stanford Univer- 

 sitv and to the city of San Jose, and crosses the 

 main line of water-supply from the Crystal Springs 

 reservoir to the city of San Francisco; it is, presum- 

 ablv, along this fault that the displacement reported 

 in the newspapers took place. There are indications, 



thquake 



