392 



REPORT OF NATIONAL MUSEUM, 1904. 



the connection between geology and the Bible, to meet the wants of 

 the "many well-meaning persons'" who were disturbed by a supposed 

 incongruity between the principles of geology and the Mosaic narra- 

 tive. A ver}^ abstruse explanation of concretionary structures was 

 offered, Adams failing, as did many of his contemporaries, to discrimi- 

 nate between concretionary structure as it is now understood, and cer- 

 tain forms assumed by igneous rocks and due to contraction in cooling. 

 Thus he considered columnar structure in basaltic rocks as a peculiar 

 form of concretion which was due to lateral pressure such as might 

 exist between spheres compressed at the sides. 



Agassiz's glacial theories had been apparently without effect, even if 

 they were known, and icebergs were considered as sufficient to account 

 for all the phenomena of the drift. 



Fig. 37.— Ideal section of the Crust of the Earth. (After C. B. Adams.) 



Explanations. — Unstratiried rocks of igneous origin: U, granite; Sn, seinite; Pr, porphyry; Tp, trap 

 rocks; Td, a trap dyke; L, lava, with a volcano, c c being fissures through which the water of the 

 ocean penetrates to the melted lava by its conversion into steam, causing earthquakes and erup- 

 tions. Stratified rocks (represented by parallel lines) of aqueous origin: Pr S, primary strata; Tr, 

 palaeozoic rocks, or the oldest rocks which contain the remains of animals and plants; Sec, second- 

 ary rocks; Tt, tertiary strata; D, the superficial covering of sand, gravel, and loose stones, called 

 "drift." 



In 1847, the year before the closing of the survey, Adams had 

 accepted a professorship at Amherst, and in 1853, in conjunction with 

 Alonzo Gray, published as a text-book an Elements of Geology, a 

 duodecimo volume of 350 pages. Here his geological work seems to 

 have ceased. Indeed, from the date of the abandonment of the State 

 survey he devoted himself mainly to zoology, and particularly to 

 conchology, making large collections especially rich in West Indian 

 and Central American forms. While at St. Thomas, on one of his 

 collecting trips, he contracted yellow fever, from which he died in 

 1853. He is described as a man of sturdy build, medium height, with 

 large, black eyes and black hair. A man of tremendous physical 

 endurance, knowing neither fear nor what it was to be tired; but, 

 withal, a quiet and self-contained demeanor. 



Thompson, Adams's chief assistant, is represented to us as a man 

 poor in this world's goods as well as in general health, and modest 

 almost to a fault — one who from childhood had shown a passion for 

 writing books. His first publications were almanacs, which he him- 

 self sold while traveling on foot about the country. It is told of him 



