582 Scientific Intelligence. 



phate mining, the annual value of which now exceeds $6,000,000. 

 Since the beginning of active mining in 1888, to the end of 1907, 

 some 12,000,000 tons, valued at $48,000,000, have been taken 

 from the Florida phosphate fields. There is also included a bibli- 

 ography of Florida geology. 



Bulletin No. 1 discusses the underground water supply of the 

 central portion of the state. The facts are interesting, as the con- 

 ditions are peculiar in various directions. The large annual rain- 

 fall taken in by the limestone rocks yields springs notable 

 for their number and their unusual size. The basin of Silver 

 Spring, for example, has a depth of 30 to 36 feet, and the total 

 now from several vents is not less than 369,000 gallons per minute. 

 It is shown that the springs doubtless receive their water supply 

 from the rainfall of the immediately surrounding country. There 

 are two principal areas of artesian wells ; one on the east coast, 

 and the other on the southern Gulf coast. The conditions in 

 central Florida are not favorable for flowing wells. 



This bulletin will be of great value to the people of the state, 

 and to geologists in general it is interesting on account of the 

 descriptions of the underground water supplies in cavernous 

 limestone. The State Geologist reports that the Survey work 

 will be carried on particularly on economic lines, but that maps 

 are also under preparation and arrangements have been made 

 with the United States Geological Survey for a joint study of 

 the larger field problems. He is to be congratulated on the 

 character of his first year's work. h. e. g. 



3. Wisconsin Geological and Natural History Survey ; E. 

 A. Birge, Director. Bulletin No. XX. Economics Series, No. 13. 

 The Water Powers of Wisconsin ; by Leonard S. Smith. Pp. 

 xviii, 352, with 54 plates and 17 figures. Madison, 1908. — The 

 state of Wisconsin is unusually rich in its water power resources ; 

 not more than half a dozen other states in the country being so 

 well situated. As at present developed it is estimated that the 

 water power approximates 130,000 horse power; this probably 

 represents a small proportion only of the total power available. 

 This is of particular importance to the state, since it is relatively 

 distant from coal supply. In 1905 the legislature appropriated 

 $2,500 for a survey of the water powers and a report on them, 

 and to this work the IT. S. Geological Survey has contributed a 

 like sum, in addition to having expended since 1902 a large 

 amount for daily measurement of river flow. This bulletin pre- 

 sents in detail the information thus far accumulated, and the data 

 given will be of great value to those immediately concerned. 



4. The Geological Survey of Cape of Good Hope / Twelfth 

 Annual Report^ 190? ', including the following papers : (1) Chair- 

 man's Letter, p. 3 ; (2) Director's Report, pp. 5-7 ; (3) Geo- 

 logical Survey of Parts of Vryburg, Kuruman, Hay and Gordonia, 

 by A. W.Rogers, pp. 11-122, two maps and 13 figures; (4) 

 Geological Survey of Portions of Mafeking and Vryburg, by A. 

 L. DuToit, pp. 123-157, figs. 3; (5) Geological Survey of 



