52 REPORT ON NATIONAL MUSEUM, 1885. 



a quiescent though somewhat confused state, owing to the fact that 

 since the preceding July the entire euergies 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 conse- 

 quently fallen behind. The special exhibit was completed late in De- 

 cember 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 4-inch cubes; (2) a collection of some twelve 

 specimens of foreign and native marbles in the form of polished slabs ; 

 (3) a collection of 150 specimens of rock-forming minerals; (4) a collec- 

 tion 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 

 Washoe district, Nevada ; (G) a lithological collection comprising 500 

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

 forming a part 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 south-west court was removed and stored temporarily 

 in a shed outside the eastern entrance of the Museum, the court being 

 less available for exhibition purposes. By a reassignment of exhibition 

 space, this department was made to include the whole of the west-south 

 range, and a portion of the court, as heretofore. The new arrangement 

 is vastly preferable both on account of better light thus obtained, and 

 of convenience in arranging and classifying the exhibit. In May the 

 force of the department was increased by the addition of one aid, one 

 clerk, and three stone-cutters, and the preparation of a collection of build- 

 ing-stones was commenced for the American Museum of Natural His- 

 tory in New York. This collection will, when complete, comprise, not 

 less than one thousand specimens, and an equal number of thin sections 

 for microscopical study. This work was still in progress at the end of 

 June. The number of entries in the department catalogue during the 

 six months has been 486, comprising some 700 specimens. Considera- 

 ble time has been devoted to the preparation of the various exhibition 

 series, particularly those included under lithology, and historical, dy- 

 namical, and structural geology. The last three are as yet far from 

 completion, and at the present rate of progress, which is necessarily 

 very limited, must so continue for several years. On this point Mr. 

 Merrill comments as follows : 



"I may, perhaps, be pardoned for mentioning here the fact that from past experi- 

 ence I am convinced that the only satisfactory way in which these last named branches 

 of my department can bebnilt up is to allow the curator or some experienced person 

 a certain sum of money to be expended either in the purchase of collections under his 

 direct supervision or of especially desirable material. A very considerable portion of 

 the material now necessary for this purpose is of such a nature — principally on account 



