444 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1907. 
should use this ground for the erection of a large building to contain 
an aquarium, an amphitheater, a museum, and working laboratories 
for the professors and pupils at the university, all students of natural 
sciences to have free entry every morning to the garden, the library, 
and the museum. For some time past Prof. Max Weber, the curator 
of the collections, in conjunction with Doctor Kerbert, present di- 
rector of the garden, has obtained a unification of the most satis- 
factory kind between the collections of the university and those of 
the society. 
The ground donated by the city rested on a subsoil of quicksand, 
as indeed is the case with all Amsterdam. Therefore 1,740 piles were 
driven down, and three years afterwards a magnificent building was 
completed on that site. 
The aquarium, which is the only part of it that is the subject of 
this report, was arranged according to the system of continuous cir- 
culation of W. Alford Lloyd, a system that was used for the first time 
on a large scale at Paris in 1861 for the aquarium of the Jardin d’Ac- 
climatation in the Bois de Boulogne. 
Under the floor are three great reservoirs, two of which contain 
447,845 liters of sea water, the other 116,256 liters of fresh water. It 
is pumped up by two gas engines of 8 horsepower (one in reserve) 
at one end of these reservoirs; delivered into two great conduits of 
enameled iron (having cocks of ebonite) which have a small opening 
for aeration at their proximal end; it is then carried to the upper 
floors and runs the whole length of the building above the tanks. 
From each great conduit the water passes into rubber tubes, placed 
at suitable intervals, and the ends of these, fitted with glass tubes, 
are directly above the tanks. As the terminal orifice of each of these 
tubes is but a few millimeters in diameter, the jet,of water that issues 
from it has sufficient force, after being aerated a second time, to carry 
down with it a current sufficiently strong to carry away the impuri- 
ties voided by the fishes into the water of the tank; the largest of 
these matters, falling to the bottom, are removed each morning by 
the attendants by means of aspirating tubes. 
The tanks, of variable dimensions, are twenty in number. Nine 
have a total capacity of 84,695 liters of sea water and eleven a total 
capacity of 61,155 liters of fresh water. The largest has a capacity 
of 40 cubic meters. 
The service of these tanks is effected from two lateral corridors 
having glazed roofs, in which are found small aquariums for zoolog- 
ical study and thirteen reserve tanks, nine, for sea water, having a 
capacity of 18,171 liters, and four, for fresh water, of 9,095 liters. 
The water leaves the tanks in which the animals live by a lateral 
orifice and falls into a common conduit that takes it back to the reser- 
voirs in the basement at the end opposite to that from which it issued. 
