JUNE 20, 1884.] 
Poey of Havana, and by him presented to the 
Smithsonian institution. 
The color of the body of this tropical seal is 
an intense ebony black, with the hair remarka- 
bly short and stiff. The length of this creature 
is about four feet, with a circumference of the 
body near the fore-arms of three feet. Although 
Dampier seems to have been impressed by the 
large numbers of these seals in 1675, yet, as 
long ago as 1843, it was excessively rare, — as 
much so as it is to-day. This fact declares the 
industry and zeal of the old ‘oyle’ hunters, 
SCIENCE. 
753 
localities, it appears to have now well-nigh 
reached extinction, and is doubtless to be found 
at only a few of the least frequented inlets in 
various portions of the area above indicated.’’ 
Being still well known to many of the wreckers 
and turtle-hunters, it seems strange that it 
should have remained almost unknown to nat- 
uralists. 
Perhaps this figure and notice may serve to 
stimulate the attention of some one of the 
many fruit and sponge vessel owners now 
cruising in West-Indian waters, who, detecting 
who were busy in slaughtering the Monachus 
long after Dampier set the example. 
In the Jamaica almanack for 18438, Mr. 
Richard Hill published a memoir on a seal in- 
habiting the Pedro Kays, a reef of rocks lying 
off the south coast of Jamaica. This has been 
transcribed by Allen, and it seems to apply 
directly to the animal which we figure. Allen 
sums its distribution up as follows: ‘ It there- 
fore appears that the habitat of the West- 
Indian seal extends from the northern coast 
of Yucatan, northward to the southern point of 
Florida, eastward to the Bahamas and Jamaica, 
and southward along the Central-American 
coast to about latitude 12°. Although known 
to have been once abundant at some of these 
the presence of another specimen, may secure 
it, and forward the rare and valuable trophy to 
those who would appreciate and preserve it. 
Henry W. ELwiort. 
Smithsonian institution, May 21. 
THE TOEPLER-HOLTZ. MACHINE. 
Ture Toepler-Holtz induction electric ma- 
chine is too well known to need description ; 
but, as no explanation of its action is to be 
found in any book which has come under my 
observation, the following explanation may be 
of interest to teachers : — 
Consider the machine before you, the re- 
volving-plate in front. 
