REVIEWS loi 



tax upon the atmosphere and its accessions of gas from vulcanism than it 

 might otherwise seem. The intimate association of glacial deposits with 

 the Permo-Carboniferous coal beds in the comparatively low latitudes of 

 India, South Africa, and Australia furthermore raise the suspicion that some 

 of this vegetal accumulation at least may have taken place at a time when 

 there was only a limited heat-absorbing and heat-retaining blanket of car- 

 bon dioxide about the earth. 



In the special part is a discussion of the coals of the Carboniferous. 

 This is followed by an excellent description of the salient features of the 

 geology of the various coal districts in Europe in which are included some- 

 thing of the stratigraphy of the beds adjacent to the coal, the tectonics of 

 each region, and the character of the coal developed under these conditions. 

 The details of the geology of these special districts can of course be appre- 

 ciated better by the European geologist than by those on this side of the 

 Atlantic. They constitute the bulk of the book and appear to have been 

 treated with much care and discrimination. The work is a valuable con- 

 tribution to the literature of the coal formations. 



R. T. C. 



A Geologic Reconnaissance of the Island of Mindanao and the Sulu 

 Archipelago. I. Narrative of the Expedition. By Warren D. 

 Smith, Chief of Division of Mines. Philippine Jour, of Science, 

 Dec., 1908, pp. 473-99, with 23 plates and 4 figures in the text. 



Another instalment of the pioneer field work being done in the Philippine 

 Islands by this active young geologist has come to hand. Up to this time 

 very httle has been known of the large southern island of Mindanao, partly 

 because work in other important fields was more urgent and partly because 

 of the hostility of the Moros. This paper gives a brief synopsis of the pre- 

 vious work of a geographic or geologic nature, a general geographic descrip- 

 tion, notes on the people and climate, and the itinerary and narrative of the 

 expedition. The geologic observations appear with the text of the narrative. 

 An excursion was made to the summit of Mount Apo, which, so far as known, 

 is the highest peak in the Philippine archipelago. Two boiling-point deter- 

 minations gave it an altitude of 2,956 and 2,902 meters, respectively. 



In work of this sort many difficulties were naturally encountered and a 

 military escort was required as a protection against the natives. Upon the 

 basis of this reconnaissance the future detailed studies of this portion of 

 the Philippine archipelago will be planned. 



R. T. C. 



