SCIENTIFIC SURVEY. 



395 



mountain immense waves full of detritus, which subside when pro- 

 tected and deposit their load. It is this force which has made the 

 foundation land for the hotel. We have hints of a former outlet 

 of Moosehead lake into the Piscataquis river instead of the Kenne- 

 bec, which we would gladly be permitted to trace out. A knowl- 

 edge of the facts might be of practical value to lumbermen. 



We have noticed interesting terraces at several points on the 

 Androscoggin, particularly at Brunswick and Lewiston ; at Ando- 

 ver on Ellis river; on Saddleback stream; on Moose river; on 

 Sandy river ; and on the Penobscot. But our limits forbid us to 

 describe them. 



Siliceous Marl. 



We will now present an interesting letter from Professor Bailey 

 of Frederickton, N. B., upon the siliceous marls, or diatomaceous 

 earths of Maine. 



Pkof. C. H. Hitchcock: 



Dear Sii' : — You have requested me to prepare for publication a 

 notice of the microscopic Flora of the State of Maine, with a few 

 remarks on the value of "diatomaceous earths" in an economical 

 point of view, and also as throwing light upon certain disputed 

 questions of geological history. 



It might at first seem to be of little value to prepare for a report 

 on the agriculture and geology of a country, an account of animals 

 and plants so exceedingly minute as to be in the great majority of 

 cases absolutely invisible to the unassisted eye. Of what practical 

 value, we are apt to ask, can the fossil skeletons of beings so mi- 

 nute that fifteen thousand millions may be included in the space of 

 a cubic inch be to the farmer or to the geologist ? Is there any 

 way in which the former can employ them in promoting the fertility 

 of the soil, or can they aid the latter in deciding upon the geologi- 

 cal age of deposits and formations, from which all other traces of 

 organic life have disappeared ? I shall endeavor to show that to 

 both, but especially to the latter, the study of their numbers, dis- 

 tribution, and specific characters, is a subject of the greatest inter- 

 est, as well from a practical as from a theoretical point of view. 



Without entering into the details of the structure and mode of 

 growth of the microscopic Algae, it may be sufficient to say, that 

 notwithstanding their minute size, so incredible are their numbers 

 and so rapid their multiplication, that their accumulating skeletons 



