LIFE IN RIO CONTINUED. 95 



that of Minas Geraes. A survey of the Dom Pedro Rail- 

 road, made under his direction by his two young friends, 

 Messrs. Hart and St. John, is also an excellent beginning 

 of the work in this department, and his own observations 

 on the drift phenomena have an important bearing on 

 the great questions on which he hoped to throw new 

 light in coming here. The closing words of a lecture 

 delivered by him last evening at the Collegio Dom Pedro 

 Segundo will best express his own estimation of the facts 

 he has collected in their bearing on the drift phenomena in 

 other parts of the world. After giving some account of 

 the erratic blocks and drift observed by him at Tijuca 

 and already described in his letter to Mr. Peirce, he 

 added : " I wish here to make a nice distinction that I 

 may not be misunderstood. I affirm that the erratic phe- 

 nomena, viz. erratic drift, in immediate superposition with 

 partially decomposed stratified rock, exist here in your 

 immediate neighborhood ; I believe that these phenomena 

 are connected, here as elsewhere, with the action of ice. 

 It is nevertheless possible that a more intimate study of 

 these subjects in tropical regions may reveal some phase 

 of the phenomena not hitherto observed, just as the in- 

 vestigation of the glacial action in the United States has 

 shown that immense masses of ice may move over a 

 plain, as well as over a mountain slope. Let me now 

 urge a special study of these facts upon the young ge- 

 ologists of Rio, as they have never been investigated and 

 their presence is usually denied. If you ask me, * To 

 what end ? of what use is such a discovery ? ' I an- 

 swer, It is given to no mortal man to predict what may 

 be the result of any discovery in the realms of nature. 

 When the electric current was discovered, what was it ? 



