580 
Peirce’s binocular results obtained by looking 
through a tube 35 centimeters in diameter and 
2 meters long. The mean deviation for the 
horizontal then becomes (average’ of 29 sub- 
jects) —.25° and for the vertical —.56°. The 
settings are so nearly correct that the direction 
of the error cannot be regarded as significant ; 
in both sets of observations the excess in num- 
ber of those who tended to one type of error 
was not very great upon those who tended to 
the contrary type. I also investigated the errors 
for oblique settings. These proved to be much 
greater, on the average about nine times as large, 
and with a pronounced tendency to set both the 
oblique lines in a position nearer the horizontal 
than the two ‘ideal’ oblique lines making 
angles of 45° with the horizontal and vertical. 
In the same group of contributions from the 
Laboratory of the University of Wisconsin may 
also be, found a study of the accuracy with 
which lines could be set in given positions, when 
a model or copy was furnished; and a study of the 
accuracy with which angles may be reproduced. 
The variations in the manner of estimating 
which Professor Peirce has introduced are ex- 
tremely interesting and contribute something 
of value to the determination of the factors 
which influence such judgments of position. I 
can recall that at the time we were engaged in 
these investigations, I had in contemplation a 
set of experiments in which the subject should 
be required to set vertical and horizontal lines 
in a room in which contained no true verticals 
or horizontals or rectangular dimensions. The 
floor was to be slightly out of the horizontal in 
one direction, the ceiling in another, while the 
walls might present various kinds and degrees 
of divergence from the vertical. How far such 
an unusual environment might effect one’s esti- 
mate of the true horizontal and vertical seems 
an interesting subject of inquiry. 
‘ JOSEPH JASTROW. 
PSYCHOLOGICAL LABORATORY, UNIVERSITY OF 
WISCONSIN, MADISON, WIS8., October 5th. 
THE THIRD PRINCETON EXPEDITION TO 
PATAGONIA. 
Mr. J. B. HATcHER and his assistant, Mr. 
O. A. Peterson, have returned from their third 
exploration of Patagonia, where they were sent 
SCIENCE. 
[N.S. Von. X. No. 251. 
by the Geological Department of Princeton Uni- 
versity. The work has been highly successful 
and admirably supplements that of the two 
previous journeys. We hope to give later a 
more detailed report of the results of the expe- 
dition, but may state at present that the party 
sailed from New York on December 9, 1898, 
and returned August 17, 1899, bringing very 
extensive collections of both vertebrate and in- 
vertebrate fossils of Patagonia, together with 
much material illustrating the zoology and 
botany of that region. The work of cleaning 
and preparing these great collections for study 
and publication has already made good prog- 
ress, and is being pushed forward as rapidly 
as possible. 
In a recent report Mr. Hatcher summarized 
the results of the work for the last three years 
as follows : 
““(1) A good preliminary geological survey 
of that part of southern South America, lying 
between the Andes on the west and the At- 
lantic on the east, and between the Straits of 
Magellan and the forty-seventh parallel of 
south latitude, sufficient to serve as a basis for 
a geological map of the region. 
“(2) Very extensive and complete collections 
of fossils from all the different fossil-bearing 
horizons known to that region, with the one 
exception of the Pyrotherium beds. 
“(3) The discovery of four distinct and pre- 
viously unreported geological horizons. 
‘‘(4) A collection of more than one thousand 
skins and skeletons of recent birds and mam- 
mals, embracing about one hundred and fifty 
species of birds and fifty species of mammals, 
and fairly representative of the mammalian and 
avian life. 
“¢(5) Extensive collections of the fresh water, 
terrestrial and litoral invertebrate life. 
“‘(6) Botanical collections, especially of the 
mosses, Hepaticee and flowering plants, not in- 
cluding the grasses and sedges.”’ 
(7) To the above should be added a large and 
very valuable series of photographs, illustrating 
the geology and physical geography of Pata- 
gonia. 
It is hoped that a series of adequately illus- 
trated monographs will be issued from the 
Princeton museum containing the results of the 
