Burlington weekly free press. [volume] (Burlington, Vt.) 1866-1928, 1877-04-27
VOL. XIX. NEW SERIES. VOL. XXI
From the Boston Journal Of Commerce.
Reading for the Scientific,
INTERESTING TORPEDO EXPERIMENTS IN CHER


Reading for the Scientific.
INTERESTING TORPEDO EXPERIMENTS IN CHER
BouRG.
Some very interesting experiments were
made few days ago at Cherbourg with the
little submarine vessel called the ''Thorney-
croft. 1t was the first occasion OF testing
IN French water whether n torpedo could be
launched against ship in full sail. Accord
ingly Admiral Jaurez, who commands the
squadron, ordered q disabled ship, the bay
onnaise," during rather rough sea, to be
towed out by u steamer belonging to the
navy.
A second lieutenant, NJ. Lemoinne, was
sent for, and informed that he had been Sc
lected to make the experiment of launching
the 'Thorneycroft' against the "Bayonnaise
while both were in full sail. He accepted
the mission without hesitation, picked out
two enginemen and pilot and went down
with them into the interior of the "Thorney-
croft, of which only small part was above
water, this visible portion being painted of u
grayish color, so as to be easily confused
with the sea. The torpedo was placed so rs
to project from the bow of the vessel, at the
extremity of which were two lateen sailyards
about three metres in length. The towing
steamer then took up its position in front of
the squadron, md the ''Thorneycroft" also
assumed the position assigned Tor it; an ill
terval of three or four marine miles separa-
ting the torpedo and the ''Bayonnaise."
On a signal being given, both were set in
motion. the steamer advancing in straight
line, and the "Thorneycroft'' obhquely, so
as to take the "Bayonnaise" in flank. The
steamer tug went at II knots an hour, going
at full speed in order to escape the ''Ihor-
neycroft." The latter went at nineteen knots
an hour, a rate not attained by iany vessel in
the squaeron. The chase lasted about an
hour, the squadron keeping i'll the rear so as
TO witness the operations.
At the end of that time the distance be-
tween the 'Thorneycroft" and "Bayonnaise"
had sensibly diminished, ana at given mo-
ment the former, in order to come up with
the latter at the requisite distance, had to
slncken speed to eight knots an hour. The
whole squadron watched this last phase of
the struggle with breathless interest, and
people asked themselves whether the shock
of the torpedo would not infallibly destroy
the little vessel that bore it. 1t was feared
that the lives of the second lieutenant, Le-
moinne, and his three companions were alb
solutely sacrificed. However, the two yes-
sells got visibly nearer.
All at once the "Thorneycroft" put on
last spurt, and struck the "Bayonnaise' with
its whole force on the starboard bow. The
sea was terribly agitated, a deafening report
was hear d. and the .Bayonnaise," with rent
big as q house sank with wonderful rapidity.
As for the ''Thorneycroft." rebsunding by
the shock about fifteen metres of, even be-
fore the explosion occurred, it went round
and round for few moments, anu then
quietly resumed the direction of the squad
ron. No trace remained of the '.Bayon-
naise;" it was literally swallowed up by the
sea.
POSSIBLE REDIsCovERY OF LOST ART.
1t was well known that under the influence
of moist air and in the course of great lengths
Of time, certain kinds of glass lose their
transparency and become covered with opal
escent layers, whith are easily cracked of.
This occurs most frequently with glass that
has been long buried In the earth. In the
collection of ancient relics e1humed at Cy-
prus by General Di Cesnola there are abund-
ant examples of glass bottles, cups, vases
ETC., which are as brilliantly iridescent as is
carved from the pearl shell. The reason for
this change, as we have already explained, is
that the alkaline base in the glass combines
with the carbonic acid of the air, setting free
the silicic acid of the material. Then the
alkaline carbonate SO formed is washed away
by water. and in place of the glass we have
nearly pure silicic acid. This has been proved
to be the fact by actual analysis of some of
General Di Cesnola's specimens. But there
is good cause to believe that the ancients
were in possession of processes for produc-
ing this iridiated glass in brief periods of
time; and it also appears that the glass
workers OF China and Burmah have like
knowledge. In April of last year. we noted
the fact that specimens of the Chinese glass
haI haa,, 70 C1ap,a,Jnt taI
French chemist, for examination. We now
find in the report of recent meeting of the
French Academy of Sciences that in con-
junction with NJ. Frenzy, the above scientist
has succeeded in reproducing the iridiated
glass, and that numerous fine specimens
have been exhibited before the aforesaid So
ciety. The process, which is said to be GER
tain in its results consists simply in sub
mitting ordinary glass for SIX or seven hours
to the action of water containing 10 per cent.
of hydrochloric acid at pressure of from
to atmospheres. corresponding to tenn
perature of about 4So Fab. The beautiful
glass thus quickly produced will doubtless
find many ornamental applications.
DEaIAGNArIzISG TOOLS.
The following from the Art Journal will be
of interest to workers with fine steel tools:
A correspondent in your journal asks how to
remove the magnetism from a kit of tools.
So far as the actual experience of the writer
goes there is but one ''sure cure, that is to
heat the tools to red heat. If they are
plain, common tools, this will be the easiest
and quickest way. The time expended is
not necessarily lost, as there will be an OPP
portunity to harden and temper them special
ly for the use to which they are put. A large
share of common tools are very far from be-
ing properly tempered. But whero tools are
such as would be injured by the heating or
which the owner does not feel competent to
harden and temper properly, there is another
way to remove the magnetism. The writer
has never tested it himself, being very care
full not to have any occasion for the use of
such process. But it is strongly recon-
mended by others whom he knows to be
and experienced mechanics. 1t
is to take the common bar or horse shoe
magnet, and magnetize the tools by rubbing
it over them lengthways, either in actual con-
tact or very near to them, until they are well
charged, then rerpSe the direction of the
motions of the magnet and take the magnet
ism out. The object of the former part Of
the operation is said to bo to make sure of
the polarity of the article SO that the reversed
motions will be certain TO take the magnet
ism out, because the former had put it i'll.
This seems reasonable. for everybody has
his jack-kniie with poker, and
it by reversing the process.
The only apparent difficulty would be to stop
Just at the right time, instead of going on
and getting the article re-magnetiZed only
with the poles changed. But this could be
effected by frequent tests dipping the piece
into clean, fine, dry iron filings, and the mo-
ment they ceased to be attracted at all, the
operation would be considered completed.
'BII.u's QUEER Customer funny old