256 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. 8 In addi- 

 tion 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 astro- 

 nomical tables of Maurice. [Query, made at his observatory at Mauritia or 

 dedicated to Maurice?] 



From certain statements found in the various prefaces and introduc- 

 tions 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 prac- 

 tically 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. 



"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. 



