Nathaniel Bowditch The Practical Navigator


Captain Prince had also retired from seafaring (at the venerable age of thirty-five). He had his fine white house in Salem, which he kept well stocked with good wines, Havana cigars, and mementos from past voyages. Relations between him and Bowditch seem to have been somewhat strained at this time; Bowditch found few reasons to visit his old friend.

In spite of the fact that this must have been one of the most trying periods of his life, it was not all lonely work. In October of 1800 he married again, this time his cousin, Mary Ingersoll, a strapping, handsome country girl who loved the solitary little mathematician with all her heart. The marriage was extremely happy, and no doubt the affection of this devoted wife helped Bowditch finish the enormous task he had set himself. Mary wanted nothing more than to see that her husband had the chance to finish his book; like poor Elizabeth before her, she had complete faith in him and in what he was trying to do.

At last the final calculation had been made and meticulously checked. The manuscript, which Bowditch called The New American Practical Navigator , was delivered to Blunt, who instantly recognized the value of what he held in his hands. Rather than try to publish it immediately in America, he took it to London—to, of all places, the publishers of Moore’s New Practical Navigator , which he had previously pirated! These people were understandably cool to Mr. Blunt and his manuscript from America, but after a careful examination of the work they also recognized its value and undertook to bring it out. The New American Practical Navigator appeared in Boston in June, 1802, simultaneously with the English edition. It offered to the unsuspecting world more accurate and useful information on ships, the sea, and all things maritime than had ever been seen before.

As much as, if not more than, Matthew Fontaine Maury, the great American chart maker and oceanographer, Nathaniel Bowditch placed all future navigators in his debt. For the first time, men could measure the heavens and in perfect faith entrust their destinies to the paths of the stars. The New American Practical Navigator was not just another navigation book. It was a tool—as important as sextant or compass.

It is impossible to examine a first edition of this book and not feel, even over this great distance of time, a thrill of pride in what Nathaniel Bowditch accomplished. Even in appearance the book is impressive. The approximately six hundred pages are beautifully bound; the text, printed on excellent paper, is still clear and legible. The copperplates and sketches are painstakingly executed, exquisite in detail. The prose is simple, precise, and to the point.

It is a vast store of information for the mariner. We find chapters on winds, currents, the obligations of an owner, the duties of a master, a dictionary of sea terms, an explanation of all possible maneuvers of square-riggers at sea and the appropriate commands for their accomplishment. There are even sections on marine insurance, bills of lading, and bills of exchange.

Mathematically the book is a treasure house. Starting with simple fractions, Bowditch takes the reader calmly and logically through decimals, geometry, algebra, logarithms, on up into the more involved trigonometry and calculus of navigation, with numerous side excursions into geography, astronomy, mensuration, gauging, surveying, and the like. There is even a section devoted to “questions to exercise the learner.”

As far as the mechanics of navigation were concerned, nothing like this work had ever been seen. It corrected existing tables and made them trustworthy once and for all. There are twenty-nine tables, and Bowditch carefully listed how each was derived. He so much improved the standard method of calculating latitude that it might be said he devised a completely new one.

In addition to hit, new method, the only truly workable one at the time, of computing longitude by lunar measurements, the book also included other procedures that were entirely Bowditch’s. His sections on coasting, piloting, and marine surveying incorporated original tables and systems relating to the distance of visibility of objects at sea, and are still in use.

Except for some interest in British naval and shipping circles, however, the book caused hardly a ripple in the maritime world. But in the realm of scholars and mathematicians, the genius of its author was recognized instantly. Bowditch was made a fellow of several scientific societies in Great Britain. At home, Harvard University offered him a degree, which he accepted, and a chair in mathematics, which he refused. But more than honors, more than degrees, more than teaching jobs, Bowditch wanted vindication and approval; he wanted his book, his methods, to be used by those for whom they were intended—the men who took ships to sea, and particularly Salem men. Yet among seafarers, old customs and ways die hard. There is nothing in the record to indicate that the New American Practical Navigator was welcomed enthusiastically by the mariners of Salem or anywhere else. What should have been for Bowditch a time of joy and satisfaction, again must have been a time of bitterness. He appears, during this period immediately after the publishing of his book, to have had no intimates, except for his family. He stayed at home in Salem, doggedly hoping against hope for a change of some kind.