Charts were made in very ancient times but they were crude and almost useless. The first nautical maps appeared in Italy at the end of the thirteenth century, and it is said that Bartholomew Columbus brought the first one to England in 1489. The close of the sixteenth century saw many map makers at work, including Gerard Mercator whose name is perpetuated in the familiar scale charts in our geographies known as "Mercator's projection" which were the sea charts in general use. Globes were carried on ships in preference to charts in the early days and what is known as "great circle" sailing was evolved from them. Davis describes it in 1594 and it is possible that Cabot knew of the theory a century before. Such a simple instrument as a parallel ruler was not invented until late in the sixteenth century and tables of logarithms and Gunter's scale by which navigators make all their calculations were not known until the year the _Mayflower_ sailed. During the first century following the settlement of New England it is probable that the small coasting and fishing vessels were navigated by dead reckoning and not venturing far beyond the sight of land a compass was the only instrument carried. But the larger vessels sailing from Boston, Salem, Portsmouth, Newport and other ports on voyages to the West Indies, England and Spain, it would seem should have carried instruments with which observations could be made to obtain their approximate position. Mr. George Francis Dow has searched the early probate records of Essex County coast towns between 1634 and 1680, a period of nearly fifty years, and finds but thirteen references to nautical instruments in inventories and wills. Sometimes they are listed as "marriners instruments" and in one case a quadrant is valued at £1. Robert Gray of Salem, who died in 1661, possessed a "quadrant, a fore-staffe (cross-staff), a gunter's scale, and a pair of Compasses." John Bradstreet, who died at Marblehead the previous year, owned "3 small sea books" valued at £1. 6s. The inventory of the estate of Jonathan Browne of Salem, who died in 1667, discloses a "fore-staff," and that of the estate of John Silsby of Salem, taken in 1676, lists "marriners instruments and callender, 14s." In a very detailed inventory made in Salem before a notary publick on Nov. 4, 1702, of the equipment of the ship _Province Galley_, 90 tons, owned by Roger Derby, the only instruments for navigation that appear are "Two Compasses, two ha[lf] ho[ur] glasses, a ha[lf] Watchglass, a ha[lf] minute glass ... a hand lead line, a deep sea lead line."