(or 
what may prove to be new species of fishes, certainly new to Minnesota; 
collected a great many insects, some of them new, and a number of rep- 
tiles. Besides these, extensive data were secured concerning a number 
of fishes, valuable histological and embryological material was preserved, 
and a number of anatomical preparations were made. There is no better 
way, it seems to me, to study the fauna and flora of a river than by such 
a‘ floating laboratory, and I wish to strongly commend the plan to any 
persons who are considering plans for such study. 
The Megalops now lies anchored at Red Wing Minnesota, on the Mis- 
sissippi River, and it will likely continue on down the river the coming 
season, after which it may become a part of the equipment of a permanent 
biological laboratory on the Mississippi, which it is hoped will soon be 
established by the University of Minnesota. 
Tests on Some Batt anp ROLLER BEARINGS. 
By M. J. GoLpen. 
These tests were made to determine the comparative friction of ball 
and roller bearings when used for shafts under ordinary shop conditions, 
so the simplest forms obtainable were used, and they were tested at such 
speeds as usually occur in shop practice. When used in shop practice 
two or more of these bearings are placed side by side and in this way an 
ordinary hanger or other such piece of apparatus is built up. In the test 
the unit of the maker was taken for the size tested and no effort was 
made to establish any relation as to comparative sizes. 
The bearings selected were for shafts one and fifteen-sixteenths inches 
in diameter, and as the shaft turns in direct contact with the rollers, the 
spindle used was a piece of regulation, cold-rolled, shop shafting of this- 
size. This piece of shafting broke down before the bearings were affected. 
The ball bearings, of which three were used, were of the form shown in 
fig 1. Im this figure the full form for a shaft is shown. In the test 
the bearing at one end was used. This consists of an inner ring of case- 
hardened steel fitted closely to the shaft and having a V groove cut around 
the outside. The balls travel between this groove and a corresponding 
