I06 REPORTS ON INVESTIGATIONS AND PROJECTS. 



BIOLOGY, MARINE. 



DEPARTMENT OF MARINE BIOLOGY. TORTUGAS. FLORIDA.* 

 By a. G. Mayer, Director. 



The laboratory yacht Physalia remained moored in the Miami River 

 throughout the hurricane season of 1905, and in February she was thor- 

 oughly overhauled and refitted. An awning was constructed to extend 

 from stem to stern, thus shielding the decks from the intense heat of the 

 tropical sun. The decks were recalked and varnished. The engine was 

 placed in the best possible condition, and the exhaust pipes were renewed 

 where corrosion had attacked them. The vessel was also provided with 

 large hood ventilators which are a necessity in the tropics, in order to 

 permit of microscopic studies being carried out in the cabin. The yacht 

 was also hauled out and her hull found to be free from the attacks of 

 Teredo ; and in order to better insure her safety in this respect the brass 

 sheathing was made to entirely incase her keel, and a false keel was placed 

 on for protection in the event of her going aground. 



In addition to these extensive repairs and alterations in the Physalia 

 a new launch, the Sea Horse, was constructed for the Department by 

 Stearns & McKay, of Marblehead, Massachusetts, and shipped to Key 

 West early in March. This launch is designed to withstand heavy 

 weather in the open sea in order to transport investigators to and fro 

 between Key West and Tortugas. She is 27 feet long, and is furnished 

 with two 6-horsepower naphtha engines, and with twin screws, thus 

 insuring her against the probability of a total breakdown of her machin- 

 ery while at sea. This launch is provided with a comfortable cabin, 

 and can travel more than 400 miles with her supply of naphtha. She 

 develops a speed of 8 knots in average weather, and owing to lack of 

 spars and top hamper she is but little retarded by head winds. 



The Department is thus provided with five boats, the 58-foot 20-horse- 

 power ketch Physalia; the 27-foot twin-screw 12-horsepower cabin launch 

 Sea Horse; a 22-foot 4-horsepower dory; a small i-horsepower launch, 

 and a rowboat. 



With these vessels it is possible to cruise anywhere within 150 miles 

 of the laboratory ; the Physalia being a thoroughly seaworthy vessel de- 

 signed especially to withstand West Indian hurricanes. 



Prof. William K. Brooks and his assistant, Mr. Carl Kellner, of Johns 

 Hopkins University, joined the Physalia at Miami, Florida, in March, 

 and a few days were spent in a study of the pelagic fauna of the Gulf 



* Report for the year ending September 30, 1906. Grant No. 308. $15,000 for investi- 

 gations and maintenance. (For previous reports see Year Book No. 3, pp. 50-54, and 

 Year Book No. 4, pp. 108-124.) 



