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THE POPULAR SCIENCE MONTHLY

especially) with such an abundance of natural-history material, that at the end of a one hundred years it had not all been worked up.

That these collections were largely the work of Marcgrave seems more than likely. And indicative of the care which he bestowed on his specimens and of the value set upon them as a result, the following quotation from Manget is in point.

Samuel Kechelius saw sold at Harlem for 4,000 florins a book of dried Brasilian insects, the names of all of which were written in Marcgrave's own hand.

With reference to Marcgrave's mathematical and astronomical work, we know little about its extent and even less about its content. That he drew plans for camps, cities and fortifications, and made maps of the regions explored, we are told by the writer in Manget.[1] In addition to these there were MSS. of more important character brought back by Count Maurice from Brazil.

De Laet, who was Marcgrave's literary executor, tells us in the preface to Marcgrave's part of the 1648 folio that from notes found among Marcgrave's papers it is clear that our author had worked up his mathematical and astronomical data into a great work in three parts under the title, "Progymnastica Mathematica Americana."

The first section is on Astronomy and Optics and contains a review of all the southern stars found between the Tropic of Cancer and the Antarctic Pole; many various observations of all the planets and of eclipses of the sun and moon worked out in an original way; new and true theories of the inferior planets, Venus and Mercury, based on special observations; a theory of refractions and parallaxes setting forth the greatest obliquity of the ecliptic; and finally data not only on sun spots but also on other astronomical rarities. The second section is geographical and geodetical, containing a theory of the longitude of the earth and manner of computing the same, demonstrating the true dimensions of the earth from special observations, and disclosing the errors of geographers ancient and modern. The third is based on the two preceding and consist of the astronomical tables of Maurice. [Query, made at his observatory at Mauritia or dedicated to Maurice?]

From certain statements found in the various prefaces and introductions to both the 1648 and 1658 folios, it seems rather probable that Piso had charge of these MSS.; but at any rate it is certain that practically all of the papers in the first and second sections were by order of Count Maurice or De Laet turned over for editing and publication to Golius, the Leyden astronomer and former teacher of Marcgrave. Unfortunately, they seem to have been lost, at any rate, it is certain that they were never published.

  1. Driesen, De Crane and Van Kampen say that Marcgrave worked up four special charts of Brazil, and that Count Maurice after his return to Holland had them etched on copper and had many copies made. These must be. the maps which Manget says were common ornaments on the walls of the vestibules in the homes of the better class of Dutchmen. Later a second edition was printed, but as Margrave's name was omitted from this all credit was lost to him.