REPORT OF THE SECRETARY. 39 



the exhibition at Vienna, in 1873. It was presented by the commis- 

 sioner, Mr. Daunfeldt, to the Philadelphia Centennial Commission, but 

 was not exhibited, having been stored in Philadelphia until the past- 

 summer, when it was presented by the Centennial Board of Finance to 

 the United States. 



This exhibit was quite equal in value to that displayed by Sweden at 

 Philadelphia, and which became the property of the Institute of Mining 

 Engineers. The collection, amounting to about fifteen tons in weight, 

 was carefully packed under the supervision of Mr. Thomas Donaldson, 

 and forwarded to the Institution. 



Messrs. Dunn & Brothers, of Philadelphia, presented three boxes of 

 China clay from an establishment in England, of which they are the 

 agents. 



Surveyors-General Wasson and Hardeuburg have continued their con- 

 tributions of specimens illustrating the character of the ores in newly- 

 discovered miuing regions in Arizona, &c. Mr. C. W. Derry presented 

 a collection of silver ores from the J. D. Dana Mine in Colorado. Mr. 

 Keynokls, the United States minister to Bolivia, has transmitted a series 

 of copper ores of that country, and a large number of single specimens 

 have been received, sent in for the purpose of identification. 



It will be seen, from the preceding enumeration and from the list of 

 donations, that the collections are of varying magnitude, some being 

 exhaustive and covering all branches of natural history, others limited 

 to a single department and sometimes to a single specimen. All these, 

 however, find their place, a single object sometimes being more valuable 

 than a large collection in supplying an important gap. 



The most important sources of supply, as will be understood from what 

 has already been said, have been the several government expeditions, 

 particularly those of Lieutenant Wheeler and of Major Powell; the 

 articles of general and natural history and ethnology obtained from these 

 two officers being of very great magnitude and value. 



The thanks of the Institution are due for 1877, as in previous years, 

 to the Alaska Commercial Company, for disinterested and important 

 services in acting as its agent in receiving and forwarding specimens 

 and supplies transmitted between the Smithsonian Institution and its 

 correspondents on or near the Pacific coast of North America and Asia; 

 in giving free transportation on its vessels to their correspondents and 

 their equipment and collections, as well as subsistence and quarters at 

 its stations; in supplying objects of natural history, valuable in a scien- 

 tific point of view as well as commercially; and in every possible way 

 giving to the Smithsonian Institution the benefit of its organization and 

 opportunities in the most liberal manner, and, in all cases, without any 

 charge beyond that required for the reimbursement of moneys actually 

 paid. 



The United States Signal Service, under General Myer, has taken 

 part, with its usual liberality, in the efforts of the Institution to in- 



