“Mr. Horace E. Ware read the following paper:

A FORGOTTEN PRIME MERIDIAN.

The ‘Almanack for the Year of our Lord 1647. … By Samuel Danforth of Harvard Colledge, Philomathemat,’ Cambridge, the second earliest American almanac extant, states on its title-page that it is “Calculated for the Longitude of 315 degr. and Elevation of the Pole Arctick 42 degr. & 30 min. & may generally serve for the most part of New-England.‘

While I have not made exhaustive research, I have examined several Massachusetts almanacs subsequent to that of 1647 and well into the eighteenth century with regard to the longitudes on their title-pages, and will give a brief account of their ways of stating the same, assuming that the longitude intended is that of Boston where no place is named. …”

Reference Data:

Publications of the Colonial Society of Massachusetts, Vol. 12, by Colonial Society of Massachusetts, pages 382 - 398