60 Report of the President 



Assistant Curator and outlined on the globe surface by Mr. A. 

 Briesemeister. Eight casts of this ocean relief have been 

 made, and they will serve as excellent bases for modeling the 

 continental relief of North America during eight periods of its 

 history. They will illustrate the distribution of the epiconti- 

 nental seas, in which certain sediments and fossil shells were 

 deposited. As paleogeography is still a subject of research, it 

 will take some time to gather the data and complete the models. 



With the aid of the excellent topographic map of the Grand 

 Canon which the United States Geological Survey has pre- 

 pared, the Assistant Curator is constructing a relief model of 

 the Grand Canon, Mr. P. B. Hill assisting. 



The Weyer's Cave Exhibit, the installation of which has been 

 in charge of Mr. Peters of the Department of Preparation, 

 was completed and opened to the public in December. 



In connection with the work on the Porto Rico collections, 

 the Assistant Curator, with the aid of Mr. A. Briesemeister as 

 draftsman, prepared two excellent maps, one of Porto Rico, 

 the other of the West Indian region. 



Many inquiries concerning the seismograph were answered 

 during the year. Plans and specifications were forwarded to 

 Professor H. F. Reid of Johns Hopkins Univer- 

 eismograp g .^ Baltimore. Excellent records of earthquakes 

 were secured, many of which were consulted in the courts of 

 New York and near-by States. The great dynamite explosions 

 on Black Tom Island, New Jersey, were not recorded, although 

 many down-town buildings in New York were affected. This 

 is an instance showing that, although great dynamic explosions 

 produce violent air concussions, they do not perceptibly affect 

 the earth. 



With the assistance of Messrs. Hill, Brickner and Berlin 

 for a month, the washing, cleaning and sorting of the large 

 Porto Rico collection were finished. Dr. Jonas 

 spent about one month in helping the Assistant Cura- 

 tor with the preliminary identifications of the more important 

 groups of fossils. The fossil plants of the Porto Rican col- 



