tinuous. It seemed, consequently, clear that a house-boat or 
so-called cabin-boat of special construction, furnished as a 
biological laboratory, but with an equipment for minor experi¬ 
ments also, would meet our needs far more precisely than a 
building on shore. 
This laboratory boat (Plate III.), launched in April, 1896, 
was built at Havana from plans drawn up under my direction 
by Messrs. Gunn and McLane, of the architectural department 
or the University. A strongly built hull of Washington fir sup¬ 
ports a deck 20x60 feet, upon which is a cabin 16x56 feet. In 
building the hull, extraordinary pains were taken to obtain a 
steady construction. A tliree-inch solid bulkhead was run 
lengthwise through the middle, and two keelsons divide the 
space between this central bulkhead and the gunwales. Lateral 
strength was given by four series of diagonal braces, set as 
* shown in Plate VI., and placed every two feet, and by three hog- 
chains run from the bottom of each gunwale over the middle 
bulkhead. Asa consequence, the floor of the boat proved to 
be remarkably steady, no tremor being noticeable in the use of 
the higher powers of the microscope on minute objects sus¬ 
pended in fluids. The interior of the hull is ventilated by 
means of four hatchways with movable covers, two at each end 
of the deck. 
The cabin (Plates IV., V., and VI.) has six large windows 
on each side, made freely movable for ventilation, and also 
transom ventilators above the windows. The roof is penetrated 
by four large ventilators, and walls and roof are made double, 
as a protection against the heat, by ceiling with Georgia pine. 
By virtue of these arrangements the laboratory rooms were 
remarkably comfortable during even the hottest weather of the 
year. 
The interior of the cabin is divided into four rooms : an 
office and library at one end 11 feet and 6 inches by 16 feet, 
occupied by the Station staff; a main laboratory 29 by 16 feet, 
primarily for visiting students and for the experimental equip¬ 
ment ; a kitchen 8 feet and 8 inches by 12 feet, with gasoline 
stove and other cook’s equipment, in which mid-day meals can 
be prepared for the Station force; and a small closet or store¬ 
room adjacent to the kitchen. The main laboratory is provided 
with tables, two to each window, and with shelving against the 
