Tax., 191 i. Annual Report of the Director. 31 



imens have been placed on exhibition. The large map in this Hall, show- 

 ing places of meteorite falls in the United States, has also been brought 

 up to date by the addition of all recent falls. New specimens have 

 here and there been added, with some rearrangement, in Halls 63 and 

 64. In Hall 65 the collection of sand-barite concretions received from 

 Prof. Gould has been added to the concretional series and the series 

 is now as a whole perhaps the largest and most complete to be seen in 

 any museum. Some small fulgurites have also been mounted and added 

 to the collection of fulgurites in this Hall and some large cave spec- 

 imens not previously exhibited have been placed on exhibition. In 

 Hall 66 a considerable rearrangement of the specimens in the wall cases 

 has been made in order to permit the introduction of new material, the 

 most important of which is the series of trap dikes in granite obtained 

 bv the Curator in Maine. Additional marble slabs received during 

 the year have been installed in Hall 67, and a number of new labels, 

 some of them descriptive, placed with the corresponding specimens. 

 Each important series of marble in this Hall is now provided with a 

 fully descriptive group label. From Hall 69 the entire series of speci- 

 mens was removed, the cases and specimens cleaned, and the specimens 

 reinstalled. This work will continue to be necessary at intervals in 

 this Hall until dust-proof cases are provided. In Hall 70 the metal trays 

 containing specimens in the form of powders or lumps have been removed, 

 painted to a color uniform with the interior of the cases, and reinstalled. 

 The appearance of the collection as a whole has thus been improved. 

 Labels have also been installed with the collection throughout, the 

 standard label holder being used. Hall 71, devoted to petroleum and 

 its products, has been entirely dismantled preparatory to a complete 

 recasing of the collection. Funds for this purpose have been generously 

 provided by the Standard Oil Company and the construction of the 

 cases is under way. Before reinstallation a complete renovation of the 

 Hall will be made. The principal addition to the installation in Hal 

 72 has been that of a working model of a twenty-stamp gold mill, which 

 was constructed in the Department after designs made by the Assistant 

 Curator. The model is four feet six inches long, three feet six inches 

 high, and eight inches deep. It is placed in a wall case on the west 

 wall of the Hall. It represents a section of a gold mill with the house 

 in skeleton. Running from a mine not represented is an elevated tram- 

 way upon which an ore car is shown. At the end of the tramway is a 

 grizzly or screen with its pile of ore, followed by a crusher of the Blake 

 type modeled in wood, and an ore bin of standard type. This bin is 

 provided with a glass front which permits a view of the crushed ore 



