1C 
walls for books, note-boxes, specimens, etc., while down the 
center of the room is a sink-table 3x22 feet, covered with zinc 
and furnished with a water supply for numerous small aquaria. 
A long overhead zinc-lined tank is supplied by iron piping, 
with a screw end outside the boat to which the discharge pipe of 
a hand force-pump can be readily attached. Stopcocks and 
glass and rubber tubing make the necessary connections with 
the tanks and jars used for aquarium work, the overflow being 
carried off by drainage pipes which empty outside the hull. 
The space beneath the central table is enclosed with doors and 
provided with shelves for general storage. 
The boat has no motive power but is intended to be towed 
from place to place as occasion requires. Our steam launch 
“Illini” (Plate XI.) proved, indeed, to have sufficient power to 
transport this boat under ordinary circumstances. 
This launch, built by the Racine Boat Manufacturing Com¬ 
pany, of Racine, Wisconsin, is 25 feet long by 6-foot beam and 
is licensed to carry seventeen persons. The machinery furnished 
with it was replaced during the summer by a compound engine 
of four and a half horse power, with keel condenser. Both boiler 
and engine were designed by Assistant Professor YanDervoort, of 
the University department of mechanical engineering, and the 
engine and the speed propeller were made under his direction 
at the University shops. The launch was not designed espe¬ 
cially for speed, the distances to he covered in our work being 
usually very short. It gives us, however, a rate of about six 
miles per hour. It is entirely safe in all weathers to which it 
may be exposed in our situation—a point of special importance 
to us since our regular routine of field work must be carried out 
without reference to storm or temperature. Four skiffs of 
various sizes and a portable canvas boat complete the aquatic 
equipment. 
The more peculiar items of the field and laboratory appa¬ 
ratus are the plankton equipment, the breeding-cages for the 
aquatic insects, and a specially constructed centrifugal machine 
for the rapid precipitation or condensation, in graduated tubes, 
of the product of quantitative collections. This last is a 
modification of the centrifuge used by physicians, the tubes 
and tube carriers being the same, hut the mechanism being 
especially designed for us by Professor YanDervoort and made 
