1894.] Archeology and Ethnology. 1065 
ARCHEOLOGY AND ETHNOLOGY. 
The Age of Certain Stalactites.'— The fact has been recognized 
for some time among scientists that the formation of stalactites, under 
favorable circumstances may take place in a relatively short time. 
Nevertheless, observations uponthe exact period required for the 
growth of given examples have been rather rare, for while there has 
been abundant opportunity to compute the age of stalactites at railway 
bridges and tunnels, the various dangers which beset these delicate 
growths in such places have generally put a considerable limit to their 
age, and deprived them of conspicuous size. It may, therefore, be of 
interest to state an instance where not only the time of growth but also 
the exact size of a stalactite can be given with absolute precision. 
In the year 1873 the city of Bayreuth (Bavaria) built a reservoir 
for drinking water three kilometers southwest of the town. This so- 
called Lasser Reservoir is built in a Keupersand soil which contains 
exceedingly slight traces of lime. The water used in the basin comes 
out of the Keuper, (the uppermost of the three subdivisions of the 
Triassic period), and likewise contains lime, though in very small 
quantity. At the point shown in the illustration a spot on the ceiling 
of the arch (built across the tank to proteet the water from pollution 
H. C. M.) stalactites of remarkable size had formed in 1893. Suppos- 
ing that they had begun to form by the infiltration of surface water 
through the arch immediately upon its completion in 1873, they could 
not have been more than twenty years (1873-1893) old, and as the 
photograph recently taken from nature shows their length to be be- 
tween 60 and 80 centimeters, they must have grown on an average of 
from 3 to 4 centimeters a year. The reservoir was first used in 1874, 
the tank under the arch remaining full of water until the present year, 
when in the course of the summer, the water was drawn off for repairs, 
and an opportunity afforded of observing and detaching some of the 
stalactites. A great number of the finest specimens were broken 
through the ignorance of workmen. In a damp walled chamber ad- 
jacent to, though not included in the area of, the basin, hung whole 
rows of stalactites from 20 to 30 centimeters long. These were 
extremely fragile and very difficult to remove without breaking. 
! This department is edited by H. C. Mercer, University of Pennsylvania. 
*Translation from the original German. 
