REPORT OF DEPARTMENT OF PHYSICAL GEOLOGY. 231 



materially to the value of their collections by accompanying them with 



full and explicit notes regarding the Locality and occurrence of the 



specimens found. The collection of rocks and volcanic sand from the 



new volcano Of BogOSloff Island, received from Lieut, Gh M. Sloney. is 

 also of very great interest, as showing the character of the ejected ma- 

 terial from this recent volcano. This collection will probably furnish 

 material lor a special report. 



Two collections of lithologioal interest, and of importance from their 

 furnishing material not only for the Museum collections but also for 

 exchanges) have been received. The first is a fine collection of one hun- 

 dred and titty specimens of andesite and pumice from Mount Shasta, Cali- 

 fornia, collected and donated by Mr. J. S. Diller, of the U. S. Geological 

 Survey. The fact that Mr. Diller is himself at present engaged in the 

 study of these rocks and their mode of occurrence, renders the collection 

 especially valuable. The second collection is one of some hundred 

 pounds of dunite from Macon County, ^orth Carolina, the gift of T. M. 

 Chatard, also of the Survey. 



Of the collections of more strictly economic importance should be men- 

 tioned one of upwards of one hundred specimens of building stones from 

 various sources, received from Mr. J. S. F. Batchen, of Chicago, 111. 

 Mr. Batchen, from his intimate knowledge of the subject, is enabled to 

 obtain much material of this nature that would otherwise be inaccessible 

 to the department, and particularly is this the case in regard to the West- 

 ern States and Territories. A recent donation of Mr. Batchen's from 

 Mexico is of peculiar interest, the rocks being rhyolites or rhyolitic 

 t nil's, a class of material entirely unknown in the Eastern United States, 

 and, with the exception of a very few instances, but little used at pres- 

 ent for building purposes. The Esperanza Marble Company, through 

 its agent, Mr. George F. Breed, has presented a fine series of dark mar- 

 bles from the company's quarries in Vermont, and Mr. L. J. Griffin has 

 presented, through Mr. J. S. Diller, a specimen of the beautiful green 

 stalagmite marble from his quarries near Berryvale, California. To 

 Mr. J. II. Procter, the director of the State survey, the Museum is in- 

 debted for a complete series, comprising seventy-seven specimens, of 

 the building stones of Kentucky, a State which heretofore was but poorly 

 represented in our collections. The beautiful specimen of Egyptian onyx 

 marble received from Bowker, Torrey & Co., of Boston, as well as the 

 Californian marbles of like character from Messrs. J. Dimond, New 

 York, and Charles B. Hall & Co., of Boston, make an important addition 

 to our exhibition series, and ought to be noticed here also. Prof. Thomas 

 Robinson, of Howard University, has rendered the department great 

 service by collecting a full series of samples of the various strata passed 

 through in the digging of the East shaft of the water-works extension 

 in this city. In addition to the collecting of the samples, Professor 

 Robinson also made full notes on the position and character of the 



