Jan., 1910. Annual Report of the Director. 361 



ican ores; one-half case, South American ores; one case, Colombian 

 ores; one case, ores of Australia, Africa, and Europe; one case, gold 

 ores of Alaska; one case alloys of precious metals; one case salvage of 

 gold and silver wastes; one case ores of platinum; one case metal- 

 lurgy of silver-lead ores; one case metallurgy of gold, silver, and lead, 

 illustrated by models; one case large specimens South American 

 ores; one case large specimens Mexican ores; one case large speci- 

 mens New Mexico and Colorado ores; one case large specimens 

 Colorado ores; and five cases large specimens of typical gold and 

 silver ores from all parts of the world. The relief maps of Lead- 

 ville, Mt. Blanc, Carmelo Bay, and Mt. Desert exhibited in Halls 

 76 and 77 were repainted and framed during the year. Some addi- 

 tions were made to the map of Auvergne and one of the large 

 maps of the Henry Mountains was framed. About fifty labels were 

 placed in Hall 78 in number sufficient to complete the labeling of the 

 collections in this Hall and a few additional specimens were installed. 

 In Hall 79 the large mass of manganese ore from Brazil weighing 

 3,300 pounds, obtained from the St. Louis Exposition, was installed 

 upon a mahoganized base. There was also added to the exhibition 

 series in this Hall the important series of copper ores from Alaska and- 

 Washington secured by the Curator at the Seattle Exposition, and a 

 number of mercury, tin, tungsten, antimony, cobalt, nickel, and ison 

 ores from the same source. About 100 hand-written labels were made 

 for the new specimens. The West Dome not proving sufficiently well 

 lighted for the display of small specimens, the four cases of lead ores 

 previously exhibited there were removed and a number of large speci- 

 mens brought from Hall 72 to take their place. For these as well as 

 for the large specimens already on exhibition in the dome, neat 

 mahoganized bases were provided and the general appearance of this 

 hall much improved thereby. A number of important specimens 

 have during the year been prepared in the laboratory of vertebrate 

 paleontology for exhibition. The largest of these was the mastodon 

 skull with one tusk obtained from Yorkville, Illinois. Although this 

 skull was nearly complete when received, some restoration was found 

 necessary to insure its preservation. The restorations made were 

 based on careful studies of skulls both of ancient and modern 

 elephants. Considerable treatment of the tusk was also found 

 necessary on account of its strong tendency to fall apart, and 

 long experimentation was required before a satisfactory mode of 

 preservation was discovered. By imbedding the tusk entire in 

 paraffin, however, and then removing the excess of paraffin, a 



