REPORT ON NATIONAL MUSEUM. 269 



pounds tensile strength per square inch. This suite includes a very full 

 series of the different varieties of the ore and its associates from a pure 

 siderite through its various stages of decomposition to a limonite, the 

 flux (oyster shells), the charcoal, both kiln and meiler, the slag, and 

 a very extensive and valuable collection of test pieces, with full records 

 of the tests extending over a series of years. 



In cataloguing the collections, 1,257 entries have been made upon the 

 Museum register, embracing 3 ,918 specimens ; of these, 535 entries were 

 of the 83 accessions received during the year, embracing 882 specimens, 

 and including 190 specimens received from Surveyor- General J. W. Bob- 

 bins, of Arizona, through the General Land Office ; the remaining 722 

 entries of 1,036 specimens were of material previously received, but of 

 which no entry had been made, derived from four sources ; 81 entries 

 of 109 specimens from the TJ. S. Geological Surveys ; 172 entries of 

 206 specimens from the U. S. General Land Office; 86 entries of 100 

 specimens from the old Smithsonian collection, and 383 entries of 621 

 specimens from the Centennial collections. In the preparation of the 

 card catalogue 3,321 entries, embracing 5,265 specimens, have been made ; 

 these specimens have all been carefully examined by the curator in per- 

 son and 7,314 determinations of mineral species made in the ore speci- 

 mens. For the Smithsonian Institution 36 specimens have been examined 

 and the necesssary reports prepared to accompany them, and two let- 

 ters of information upon special topics have been written. Ensign A. 

 A. Ackermau, U. S. N., rendered valuable aid in the work of the de- 

 partment until the 1st of June, when he was detailed to accompany the 

 Greely relief expedition. Ensign H. M. Witzel, U. S. N., was detailed to 

 the department December 1, and has scarcely had time to become familiar 

 with the operations of the department. The clerical work has been 

 ably performed by Mr. F. J. Offutt. 



There have been two researches commenced during the year, neither 

 of which, however, has been completed. The first is an extended exam- 

 ination into the physical properties of coke with especial reference to 

 its employment as a metallurgical fuel and the prerequisites of a good 

 coking coal. There have already been examined 153 specimens from 12 

 localities, and a synopsis of the results already obtained has been pub- 

 lished by the American Institute of Mining Engineers, covering 15 

 pages of their Transactions, under the title of "Porosity and Specific 

 Gravity of Coke." 



The second investigation is upon the occurrence of free gold in galena, 

 and will soon be ready for publication. 



Any statement of the total number of specimens in the collections 

 must be largely of the nature of an estimate, as there are still a great 

 many boxes and packages of Centennial remaining unpacked. With the 

 additions received from the permanent exhibition at Philadelphia dur- 

 ing the year, I would place the total number at 30,000 or more. 



As will be seen from what has gone before, the principal attention of 



