An extract of a letter, written by Monsieur Havelius to the publisher, from Dantzick, Ju'y 5. 1670. Containing chiefly a late observation of the variation of the Magnetick Needle; together with an account of some other curiosities in those parts: Englished, as follows;

Abstract

Would to God, that those Excellent Books that are publish't in English , were, for the benefit of the whole Learned World, made Latin.