SEPTEMBER 3, 1897. | 
“Wilder has nothing to do with zoological no- 
menclature. &. TTR, 
THE SOURCE OF METENCEPHALON AND OTHER 
LATIN NAMES FOR THE SEGMENTS 
OF THE BRAIN. 
TO THE EDITOR OF SCIENCE: In my paper, 
“The definitive encephalic segments and their 
designations,’ read before the Association of 
American Anatomists last May, were offered 
objections to the action of the Anatomische 
Gesellschaft* in designating the region between 
the cerebellum and the myel (spinal cord), not 
by metencephalon, as in the last three editions of 
Quain’s ‘Anatomy,’ but by myelencephalon. This 
last was proposed by Owen for the entire neuron 
(central nervous system) in 1866 or earlier, and, 
so far as I know, its application to a single seg- 
ment was made by Huxley in 1871. Before 
printing the paper above named, I desire to as- 
certain when and by whom that region of the 
brain was first called metencephalon ; inciden- 
tally, also, the source and date of the other 
words, prosencephalon, diencephalon, thalamen- 
cephalon, mesencephalon and epencephalon, that 
have been offered as equivalents for von Baer’s 
names, Vorderhirn, Zwischenhirn, Mittelhirn, 
Hinterhirn and Nachhirn. Information through 
your columns or directly will be very wel- 
come. 
IrHaca, N. Y. 
Burt G. WILDER. 
ANDREE’S NORTH POLE BALLOON VOYAGE. 
IN ScrENCE for August 20th, p. 291, occurs a 
copy of a telegram purporting to come from Dr, 
Nils Ekholm regarding the Andrée balloon 
which is attracting so much attention. One 
serious error in the transcription should be 
corrected. It is stated that the balloon at the 
start rose to a height of 15,000 to 25,000 ft. 
The original may have been 150 to 250 metres 
(490 to 820 ft.), but could not possibly have been 
as given. To ascend 25,000 ft., over 3 tons of 
ballast would have to be thrown out, and this, 
of course, is not thinkable. At 25,000 ft. two- 
* His. W. Die Anatomische Nomenclatur. Archiv. 
titr Anat. u. Physiol., Anat. Abt., Supplement-Band, 
1895, p. 156. 
SCLENCE. 
373 
thirds of the gas would have been lost and the 
voyagers would have been in great danger of 
freezing to death. 
It is a little difficult to understand Dr. 
Ekholm’s figures. Admitting that 1,800 cubic 
feet of gas leaked out each 24 hours, entailing a 
loss in buoyancy of 123 pounds, as he gives it, 
there should still be enough gas for over 70 
days, instead of 22 to 24 days, as given. A 
leakage of 1,800 cubic feet would be about1@%, 
which is not excessive, though about 2 times 
as much as was expected. There are very few 
balloons built that have a leakage less than 
3%. The very best ‘cecum’ balloons ever 
made have a leakage of 4% in 24 hours. The 
total buoyancy of the gas was 12,000 pounds. 
The 3 men would weigh 500 and the balloon 
probably not over 1,700 pounds. Very tight 
balloons have been made in this country that 
would weigh for the same size about 900 pounds. 
This would give 80 days’ flotation. It is prob- 
able that the computation calls for even a 
heavier balloon and also for carrying the car 
all the way. It is customary, however, to 
prepare the car so that it can be used as ballast 
and at the last use the ring of the balloon. 
It is a great pity that more experience was 
not gained in a long voyage before attempting 
the extremely hazardous voyage to the Pole. 
The fact that the balloon was beyond control at 
the very start is very significant. It is doubt- 
ful if any aéronant living can release safely a 
balloon of 170,000 cubic feet capacity in a 
twenty-five-mile wind. Those who were present 
at St. Louis on June 16, 1887, will remember 
the extreme difficulty experienced in sending off 
the World balloon 160,000 cubic feet in a 
twenty-mile wind. 
If plans had been made to keep the balloon 
at 6,000 feet or so the success of the voyage 
would have been better assured. By using a 
small pilot balloon it would have been easy to 
send the overflow into the smaller balloon and, 
after the larger had leaked out enough, the gas 
in the smaller balloon could have been sent 
into the larger and the smaller used as ballast. 
At 6,000 feet the danger of rain and sleet freez- 
ing on the balloon would have been avoided 
and the currents which are far steadier and 
more rapid would have reduced the voyage by 
