a 
APRIL 25, 1884. ] 
from the ordinary fish-type can be explained 
on teleological grounds. ‘The enormous de- 
velopment of the jaws throws the branchial 
apparatus out of place, and entails its eventual 
degradation. The peculiar construction of the 
mouth, and opposability of the jaws, appear 
to be correlated with selection for food, which 
seems to consist principally of globigerinae and 
copepods, which are doubtless restrained from 
escape, with the water ejected from the mouth, 
by the structures functioning as pockets and 
whalebone. 
Another paper, largely based on the work 
of the Albatross, was that of Dr. Gill on the 
ichthyological peculiarities of the Bassalian 
realm, as he has proposed to call the deep- 
sea region. His views, which are at direct 
variance from those of Dr. Gunther, based on 
the study of the Challenger material, will be 
given in some detail in an early number of 
Science. 
In his paper on mastodons, read by Dr. Gill, 
Prof. E. D. Cope claimed that ten species were 
known from North America, of which no less 
than eight flourished during the Puerco period. 
Dr. J. S. Billings, through Major Powell, 
suggested a new method of studying crania by 
means of composite photography, and exhib- 
ited some very interesting prints taken in il- 
lustration, on each of which seven adults of the 
same race and sex were shown from in front, 
in profile, and from beneath. Sioux, Eskimo, 
and Hawaiian-Islanders were the races chosen ; 
and the method seemed capable of wide appli- 
cation with good results. 
President E. M. Gallaudet read a paper on 
the ‘combined system’ of teaching the deaf, 
which he illustrated by one of his pupils, who 
could answer questions put to him with con- 
siderable distinctness. The speaker was not, 
however, of opinion that the use of the manual 
system could be entirely dispensed with, and 
characterized as a fallacy the views supposed 
to be held by another school, — that because 
some deaf had been taught to speak by lip 
instruction, therefore all could be so taught. 
The system which Dr. Gallaudet prefers, he 
would probably consider an eclectic one, apply- 
ing to each case the method best adapted to it. 
The following gentlemen were elected mem- 
bers of the academy: Profs. EK. 8. Dana and 
Sydney I. Smith of Yale college, Gen. C. B. 
Comstock of the corps of engineers, Dr. W. 
K. Brooks of Johns Hopkins university, and 
Capt. C. E. Dutton of the U. S. geological 
survey. 
The autumn session of the academy will be 
held in October, at Newport, R.I. 
SCIENCE. 
505 
AN ARCTIC VESSEL AND HER EQUIP- 
MENT. 
A Goon portion of the science of navigation 
is devoted to the subject of safety. In navi- 
gation in the ice, that object is increased ten- 
fold in importance, and overshadows all others. 
In the history of the different arctic voyages, 
whether for popular reading or for scientific 
report, this question of safety has generally 
been considered only so far as that particular 
voyage had any thing interesting or useful to 
suggest as a result of its own adventures. 
While it is not hoped in this article to add any 
thing to our previous stock of knowledge. 
still it is possible, that by bringing together a 
statement of various dangers and difficulties 
to be met, and the methods which have been 
employed to overcome them, its publication will 
aid in an understanding of this often talked of 
arctic voyaging. 
The subject of ice-navigation embraces the 
construction of ships for this peculiar employ- 
ment, or the altering for it of those that have 
seen less severe service; their management 
under the various combinations of ice-packs, 
ice-floes, icebergs, tides, storms, currents, and 
every obstacle of the frigid zone; their care 
and preservation in the ice during the arctic 
winter ; and their liberation from this ice when 
the summer will allow them to begin again 
their experience as they prosecute their journey 
on or homewards. 
I will not dwell upon such indubitable facts 
as the quality of the ship’s material, which it 
is evident must be of the very best, be it wood 
or iron, or the almost equally apparent fact of 
the superiority of a vessel specially constructed 
for this purpose, by the hands of proper per- 
sons who have had experience in arctic navi- 
gation as well as naval construction, over the 
reconstructed merchantman or even stronger 
built man-of-war. The superiority of iron 
ships over those of wood no longer holds in 
the Arctic. The rapid conductive power of 
the former makes it almost impossible to keep 
an equable temperature without a thick inside 
coating of some non-conductor, besides the 
more rapid formation of frosts from condensed 
moistures along the outer sides of the bunks, 
causing serious diseases, and greatly aiding 
the propagation of that most terrible of all 
arctic scourges, the scurvy. ‘The superior 
strength and endurance of iron over wood, in 
the usual accidents of the temperate and trop- 
ical seas, seem to be lost when the test comes 
in the shape of severe pressure from the ice; 
the elasticity of the wood allowing it to return 
to its original shape after an almost indefinite 
