Nathaniel Bowditch The Practical Navigator


Blunt had heard of Bowditch’s genius and begged him to find out what was wrong with the Navigator . Bowditch agreed to do what he could. To begin with, he found that Moore’s method for establishing longitude was not fully reliable. Secondly, the calculations in the tables had been done so carelessly that the book was literally a mass of errors. We read in Bowditch’s journal: “Another error in Moore’s … Eight errors in Moore’s today … Five more errors in Moore …” And so on. Eventually, Bowditch was to note the incredible total of over eight thousand mistakes. Even to revise these existing tables to the point where they could be trusted, Bowditch needed a great deal of time, another long sea voyage if possible. The opportunity was to come sooner than he anticipated.

Another necessity dictated his return to the sea. During the period ashore he had married Elizabeth Boardman. He continued to work on the Moore revisions, but he quickly found the world does not pay for effort alone. There was only one way of obtaining another financial stake, and so in August of 1798, five months after his marriage, he again sailed with Captain Prince in the Astrea , this time for Spain.

Bowditch must have kissed his bride good-by with a heavy heart and deep forebodings. Elizabeth was seriously ill with consumption. In Alicante his worst fears were realized. He received word indirectly that she had died. Bowditch had never been popular in Salem, and a plaintive entry in his journal is indicative of the humble status of this heartsick and lonely man: “… none of my friends in Salem have seen fit to notify me or give me any details of the death of my beloved wife.”

The Astrea returned to Salem in April, 1799. Bowditch turned his corrections of Moore over to Blunt, and the book was copyrighted in May of the same year. In spite of his lack of personal acceptance in Salem, and in spite of his grief over the death of his wife, there was for Bowditch one ray of light. In certain circles his genius as a mathematician was beginning to be recognized. He was elected to the American Academy of Arts and Sciences. Yet in September of 1799, when his revised edition of Moore’s Navigator appeared, the title page didn’t even mention Bowditch’s name.

While the book was on the press—in July—Bowditch again sailed with Captain Prince in the Astrea , and again for Manila. Anticipating a third edition of Moore’s , Blunt had asked Bowditch to continue his corrections, but the day before the Astrea left port, Blunt appeared on board with another idea. The moment seemed right, he said, for a whole new book on navigation. Instead of continuing to revise Moore during the voyage that lay ahead, Blunt suggested that Bowditch do a book that would be truly his own—one that would have everything in it that Moore’s lacked and that would, above all, be accurate.

Bowditch immediately agreed. He abhorred the blustering, and to him stupid, men who went to sea. Their inefficiency (by his standards), their heavy-handed intolerance and slavish acceptance of dogma enraged him. On the other hand, he loved the sea deeply and was profoundly moved by the stately grace of the great square-riggers. He was fascinated at the thought of writing a book that could guide them safely about the world by means of careful, accurate mathematics. He was delighted at the idea that something of his could enable the great ships to fulfill their inherent functional loveliness and the precise, marvelous logic that had gone into their construction.

Yet Bowditch knew that, except for the vast miscellany of information he had collected in his journals, a book of his own meant starting completely from scratch. It would take years to finish, but as the coast of America dropped astern of the Astrea , he summoned up all his enthusiasm and set to work.

Ordinarily, American ships outbound to the Orient waited for the shift in the monsoon and then headed north into the Indies with a fair wind. In steady airs, with the wind from the stern, a ship would not have to tack exceedingly, and positions could be determined accurately enough to give her a reasonable chance for survival in the maze of islands that lay ahead.

Following this procedure—waiting for favorable winds—a vessel might take as long as three years to make the round trip between Salem and Manila. But Prince and Bowditch determined to sail the Astrea by the stars alone and have her home in a year or less. Prince was well aware of the chances he was taking; nevertheless, he entrusted the navigation of his ship to the little “arithmetic sailor.” When he reached the Indian Ocean, he piled on the canvas and at once headed north into the teeth of the monsoon.

Nowadays it is almost impossible to estimate the very real dangers of such a voyage. During the Astrea ’s first trip to Manila the wind had been dead astern, blowing the ship swiftly and surely to its destination. This time it was dead ahead; tacking back and forth, the ship had to fight her way mile by mile toward Manila.