42 EEPORT OF THE SECEETARY. 



Department of Minerals. — This department has been under the charge 

 of Prof. F. W. Clarke, assisted by Mr. William S. Yeates. There have 

 been made during the first half of the year 534= entries, representing 

 2,137 specimens, all of which are new accessions, except 138 specimens 

 which were found in the old collections without evidence of having been 

 previously catalogued. Eighteen sets of minerals have been sent out 

 as exchanges, comprising about 1,200 specimens, and much valuable 

 material has been obtained in return. This department was represented 

 at New Orleans by collections of the minerals from which are obtained 

 gems and ornamental stones, and also by a collection of cut and polished 

 stones. These collections attracted the general attention of connois- 

 seurs and visitors at the Exposition. The minerals were classified after 

 Dana's system, and were arranged in seven flat- top table-cases. The 

 gems were displayed in two cases, the specimens being mounted on 

 white and black velvet pads. This department did not secure a large 

 amount of new material from the New Orleans Exposition, most of the 

 mineral collections on exhibition belonging to private individuals, to 

 whom the agents were responsible for the safe return of their specimens* 

 One-half of the southwest court has been assigned to this department 

 as its exhibition space, and the collections have been removed thither. 



Department of Lithology and Physical Geology.— The, curator, Mr. 

 George P. Merrill, was on duty at the New Orleans Exposition at the 

 beginning of the year, but has nevertheless accomplished very satis- 

 factory results in the work of reinstalling the collections upon the ex- 

 tended floor-space recently assigned to this department. The opening 

 of the year found the affairs of this department in a quiescent though 

 somewhat confused state, owing to the fact that since the preceding 

 July the entire energies of the working force had been devoted to the 

 preparation of the exhibit designed for the New Orleans Exposition, 

 and the regular work of the Museum had consequently fallen behind. 

 The special exhibit was completed late in December and the extra 

 hands discharged. This exhibit consisted of (1) a collection of .358 

 specimens of building and ornamental stones of the United States in 

 the form of four-inch cubes; (2) a collection of some 12 specimens of 

 foreign and native marbles in the form of polished slabs; (3) a collec- 

 tion of 150 specimens of rock-forming minerals; (4) a collection called 

 a "structural series," intended to represent all the common forms of 

 rock structure and texture; (5) a collection of 198 specimens of rock 

 illustrating the geology and lithology of the Comstock lode and Wa- 

 shoe district, Nevada ; and (6) a lithological collection comprising 500 

 specimens of various rocks; this last together with numbers 3 and 4 

 forming a jiart of the regular educational series of the Museum. As 

 these collections were all fully described in the report of this depart- 

 ment for 1884, no further reference to them in this place is necessary. 

 The large quantity of building-stone and other material occupying 

 the space in the southwest court, was removed and stored temporarily 



