230 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



AGE OF CENTRAL AMERICAN GOLD DEPOSITS. 



Professor William M. Gabb, of Philadelphia, who is at 

 present engaged in an exhaustive geological exploration of 

 Costa Rica, has lately made a very important discovery in 

 reference to the sedimentary rock on the Atlantic slope of 

 Costa Rica ; namely, that even such portions as are auriferous 

 are not of earlier age than the tertiary. Indeed, in Professor 

 Gabb's opinion they are of miocene age, which is, of course, 

 strongly in contradiction of the hypothesis of Sir Roderick 

 Murchison that gold is of Silurian origin. 



NEW GUANO DEPOSITS IN PERU. 



The great diminution in the supply of guano on the Chin- 

 cha Islands, consequent upon the extent to which this sub- 

 stance has been transported to all parts of the world, has 

 had a very unfavorable influence upon the credit of Peru, this 

 constituting the principal resource of the country, enabling 

 it to undertake and carry on its vast system of internal im- 

 2)rovements. For the purpose, therefore, of determining ex- 

 actly what m^,j be looked forward to in this respect in the 

 future, a government commission has been quietly engaged 

 for some time, and has lately made a report. In this we are 

 informed that not only are there other guano islands yet un- 

 disturbed, but that with the amount discovered at various 

 points on the main -land the supply may be considered as 

 practically inexhaustible. At a place called Pabellon de 

 Pica the deposit is estimated at six millions of tons; at 

 Point de Lobos, two millions, and in other places two mill- 

 ions more. 



It appears that the inland deposits were worked by an- 

 cient Indians, as in them were found galleries extended as in 

 mines, with pillars left to support the roof. Many remains 

 of implements, idols, etc., were also met with. The depth of 

 the guano in some places amounted to ninety-seven meters, 

 and many of the beds were overlaid with calcareous strata. 

 Panama Star and Herald, November 7, 1873. 



GEOLOGICAL SURVEY OF PENNSYLVANIA. 



A law was enacted by the Pennsylvania Legislature, on 

 the 14th of May, providing for a new geological survey of 



