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PIONEERS OF SCIENCE IN AMERICA. 



soon afterward made Commissioner of the General Land Office, 

 and Congress having ordered a survey of the Dubuque and 

 Mineral Point districts under the direction of his bureau, he 

 selected Dr. Owen, with whose ability he was well acquainted, 

 to conduct this examination. These districts comprised eleven 

 thousand square miles of the Northwest Territory, now in- 

 cluded in the States of Wisconsin and Iowa, and the object of 

 the examination was to enable the commissioner to reserve 

 from sale those sections found to contain mineral wealth. But 

 a short time was allowed for the work, hence it became neces- 

 sary to organize a large force. The difficulties involved in 

 such a rapid prosecution of the survey are indicated in the 

 report presented by Dr. Owen to the commissioner, April 2, 

 1840. " In one month from the day I received my commission 

 and instructions," he says, "(to wit, on September xyth) I had 

 reached the mouth of Rock River ; engaged one hundred and 

 thirty-nine subagents and assistants ; instructed them in such 

 elementary principles of geology as were necessary to the per- 

 formance of the duties required of them; supplied them with 

 simple mineralogical tests, with the application of which they 

 were made acquainted ; organized twenty-four working corps, 

 furnished each with skeleton maps of the townships assigned 

 to them for examination, and placed the whole at the points 

 where their labours commenced, all along the line of the west- 

 ern half of the territory to be examined. Thence the expedi- 

 tion proceeded northward ; each corps required, on the average, 

 to overrun and examine thirty quarter sections daily, and to 

 report to myself on fixed days at regularly appointed stations : 

 to receive which reports and to examine the country in person, 

 I crossed the district under examination, in an oblique direc- 

 tion, eleven times in the course of the survey." 



It was in the spring of 1840 that William Maclure died. 

 As administrator of his estate, his brother Alexander engaged 

 Dr. Owen to assort the very extensive collection of minerals 

 and fossils which Mr. Maclure had made in the course of his 

 geological exploration of the United States and his travels in 

 this country, Europe, and the West Indies. Specific suites were 

 to be distributed to certain schools and colleges, and the re- 

 mainder was to be retained by Dr. Owen as the nucleus of a 

 museum. These directions were duly carried out. With re- 

 gard to the portion remaining in Dr. Owen's hands The Ameri- 



