SKETCH OF WILLIAM FERREL. 691 



observations ; the boy's work, like that of the man afterward, was 

 almost entirely internal and mental. Thus, at the age of twenty- 

 seven, his schooling was ended, and he left his home and went to 

 Missouri to teach. Failing health compelled him to stop work 

 for a time, and his next engagement was at a small school in 

 Kentucky, where he remained for seven years, until 1854. 



While in Missouri he had happened on a copy of Newton's 

 Principia, ordered but never called for by an earlier teacher ; he 

 bought it for five dollars, making little advance then on account 

 of poor health, but later returned to it in Kentucky. " I now be- 

 came first interested in the tides, and conceived the idea that the 

 action of the moon and sun must have a tendency to retard the 

 earth's rotation on its axis. Knowing that Laplace had treated 

 the subject extensively in the M^canique Cdleste, I was very desir- 

 ous of obtaining a copy, mostly to see what he had in that subject. 

 I accordingly instructed a village merchant, on going to Phila- 

 delphia for a supply of goods, to procure me the work, having 

 little idea of the magnitude of the work or the cost. On learning 

 the cost at Philadelphia, he did not procure it for me until after 

 writing and hearing further from me. I had now plenty to study 

 in connection with my teaching for several years." From this 

 followed Ferrel's first scientific paper. On the Effect of the Sun 

 and Moon on the Rotary Motion of the Earth, a subject to which 

 he returned with success in later years. 



In the spring of 1854 Ferrel went to Nashville, Tenn., and 

 opened a private school ; here Prof. W. K. Bowling, of the Medical 

 College, became his warm friend, and here he first turned his atten- 

 tion to meteorology, from meeting with Maury's Physical Geog- 

 raphy of the Sea. " From this book I first learned that the atmos- 

 pheric pressure was greatest near the parallels of 30°, and less at 

 the equator and in the polar regions ; and I at once commenced to 

 study the cause of it. . . . In conversation one day with my friend 

 Dr. Bowling, I told him I had read Maury's book, and he was at 

 once desirous of knowing what I thought of it. I told him that I 

 did not agree with Maury in many things. He then desired me 

 to ' pitch into him,' as he expressed it, and furnish a review for 

 his Journal of Medicine. This I declined to do, but at length con- 

 sented to furnish an essay on certain subjects treated in the book, 

 and notice Maury's views a little in an incidental way." This was 

 the beginning of the studies in meteorology, which gave a new 

 aspect to the science. The promised article was his Essay on the 

 Winds and Currents of the Ocean. It has since been republished 

 by the Signal Service in Professional Paper No. XII. 



In the spring of 1857 the third period of Ferrel's life began 

 on his accepting an offer from Prof. Winlock, transmitted through 

 Dr. B. A. Gould, to take part in the computations for the Nauti- 



