SECRETARY'S REPORT 23 



this year was restricted to large springs near the town of Pese. As in 

 the previous year, the expedition was carried on in cooperation with 

 the Panamanian Government, and in particular with the Museo 

 Nacional de Panama. 



At the invitation of Dr. George Crile, Jr., Mendel L. Peterson, 

 associate curator of military and naval history, during the first two 

 weeks of June 1951 participated in the investigation of ships wrecked 

 during the seventeenth and eighteenth centuries off the Florida Keys. 

 Two boats equipped with air compressors for use with diving equip- 

 ment and a large water pump attached to a jet hose for clearing sand 

 from objects found on the sea bottom were utilized in this underwater 

 exploration. Many interesting relics from one British ship, including 

 iron cannon barrels, 6- and 12-pound shot, fragments of Chinese porce- 

 lain and pottery, pieces of rum bottles, clay pipes, and remnants of a 

 silver-trimmed jar, were brought to the surface. 



VISITORS 



An increase of 246,340 visitors to the Museum buildings was re- 

 corded over the previous year, the totals being 2,617,226 for 1951 and 

 2,370,886 for 1950. July 1950 was the month of the largest attendance 

 with 352,147 visitors; May 1951 was the next largest with 334,844. 

 Attendance records for the three buildings show the following num- 

 bers of visitors: Smithsonian Building, 556,110; Arts and Industries 

 Building, 1,303,990 ; Natural History Building, 757,126. The average 

 daily number of visitors was 7,190. During the past 10 years more 

 than 19,445,000 visitors have viewed the exhibits in these three 

 buildings. 



CHANGES IN ORGANIZATION AND STAFF 



On October 30, 1950, Dr. Clifford Evans, Jr., whose particular field 

 of interest is Latin America, was appointed associate curator in the 

 division of archeology. 



After 42 years of association with the institution, Austin H. Clark 

 retired from active service as curator of the division of echinoderms 

 on December 31, 1950. During his incumbency the collection of echino- 

 derms grew to be the largest, and, except for east Atlantic and Med- 

 iterranean areas, by far the most representative in the world. Charles 

 O. Handley, Jr., was appointed assistant curator in the division of 

 mammals on November 28, 1950. 



After being associated with the National Herbarium for 32 years, 

 Ellsworth P. Killip, head curator since the organization of the de- 

 partment of botany, retired at his own request on September 30, 1950, 

 and to this vacancy Jason R. Swallen, who had served as curator, 



981445—52 3 



