vl Mr. Pickering’s Eulogy on 
But a more important consequence of his mathematical knowledge, 
and of his example and personal influence, was, that he infused into 
the officers and mariners an ardent desire to make themselves 
masters of the principles as well as the practice of navigation ; and, 
so intense was their thirst for this kind of knowledge, that on one of 
his voyages the twelve common seamen, who composed the whole 
crew, had acquired the method of calculating lunar observations, — 
at that day no small accomplishment even for the first and second 
officers of a ship, and one, to which a common mariner could hardly 
aspire.* This zeal for nautical knowledge was warmly cherished by 
Dr. Bowditch; he used to aid the studies of the seamen by his per- 
sonal instruction and advice ; and there can be no doubt, that a large 
portion of the nautical skill, for which his townsmen have been dis- 
tinguished, may justly be traced, directly or indirectly, to him, as its 
original source. 
At this period of his life he had acquired some knowledge of the 
French, Spanish, and Italian languages ; and several years afterwards 
he added to these the study of the German, which at that time was 
very rare among the men of science in our country. 
During one of his voyages he began his revision of the well- 
known work on the art of navigation, called “ The Practical Navi- 
gator,” which had then for a considerable time been in general use 
among persons of the nautical profession. This book, compiled 
originally by a British writer, John Hamilton Moore, was the most 
useful manual then extant on the subject. Dr. Bowditch was led 
to make an examination of the work, which he found to be over- 
* For this fact, and the astonishment manifested in various foreign coun- 
tries at his extraordinary powers of calculation, I am indebted to Captain 
Henry Prince of Salem, the intelligent commander with whom Dr. Bowditch 
made most of his voyages. 
