New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1878-05-18
SCIENCE FOR THE PEOPLE.

TESTING FOR A DISTANT EAhIHQoAhE'-ii ~
fessor Richard over of Bloomington Ind Is engaged IN
series OF experiments the magnetic currents OF the
earth I'm that locality and sent TO THE TRIBUNE some
account Of his results Daily observations are taken OF
the perurbatOns of the magnetic currents oil DOM INC
earth and air. and these kept on record Inc news
Of severe earthquake at Puerto Cabeo' ehtehung ~
Caracas on the night OF April - having come to hand
Professor owen consulted his record for that DAY ana
nearest hour and found that the magnetic now from .
: T. IN N " W. was then more variable than on any
former observed OCCASION This indicates hiagheuc
storm at that time in the earhs crust having drec
tion along line from the locality Of the earthquake to
the place OF observation in Indiana distance OF looo
miles There was disturbance OF the galVah-
ocer on April ~ in other currents than the one haed
The needle settled TO its place readily with currents from
f. TO W. and from s. T. TO " W. The coincidence oil the
disturbance with the earthquake IN time ana direction Is
not conclusive evidence OF connection, but IT'S GER
tanly nOtew Orthy. Professor owen has been aDe 10
prcdic storms from "a 4S before their arrival
by means OF his magnetic observations The range OF
detection OF the galvanometer which is observed IN the
atmospherc currents from 60 70 in quiet weather
10 $50 or 800 In the earth currents, when
storm is approaching the needle settles for few mo-
mens only any given DETECTION and keeps mp rapid
The apparatus obtaining the direction OF earth cur
rents consists In part OF an underground IRON tak ha
eight iron rods The rods driven elk feet into the
ground distances of 70 TO 100 feet from the tank and
disposed at the compass points from the tank as centre
When one wire leading from the tank and another from
rod meet a galyanomcter tie earth current IS ndi-
Gated in respect to given direction Inc prevalng
Of comparatively weak currents from to W. that give
detection Of 50 TO l2o aud OF currents from > $ L. TO
y. y. W., which usually give 202 TO 20 detection.
NEEDLESS ALARM ABOUT SHAD.-Dr. Glen
DENIM Fort Lee, n j. recently occasoned consldera-
bic anxiety by announcing the presence OF parasite
IN North River shad the occasion of some pecu-
liar sickness among his patients. The parasite Was
described differing from the trchna of pork princi-
paly in the fact OF its being larger, and hence less
dangerous since it is only the small parasite that can
pass through the walls OF the human ntcstincs and
penetrate the muscles DR.. Gendenn thought that the
fish had acquired the parasite by feeding on DIAL or
sewage while near this city, and the good people OF
Northern New-Jersey were warned to COOK their shad
very thoroughly In order destroy the dreaded pest
another physician has come to an entirely different
conclusion. The matter brought to the attention Of
Dr. T. T. APPEL of the United States Army and he finds
the had parasite Is not only six times as long as the
Tjichinu sprds but It is trtchocephalus aud not
trchlna II swallowed without cooking, the shad para
sites, II sufficiently numerous might possibly produce
some Inconvenience. bu at worst serious disease
The specimens examined found TO be Of kind not
nj all nffcgucnt in the ntcstncs Of the larger animals
including man, but easily disposed Of by medicines II
they should become annoying queer objection TO the
Fish Commissioners work has been raised 10y the North
River shad fishermen. They complain that they hnd
smaller Ash their nets, which Is said to be hybrd-a
cross between the shad and the herring. Hence they
acge that the sh-hatchery has deteriOraod the breed
of shad TO which Mr.. Seth Green replies that the by
fshcrmens catch; but that II there is any objection TO
the small fish, there is simple aud effective remedyL'
u nets Of larger meShe; by Wmci only iu'slLcu
| shad of unmixed lineage will be secured.
HEALING RAW SURrACEs.-Nearly year
ago. Dr. c. Waters of Boston. made the discovery that
tho ocarbonate Of soda II applied to burned or scaded
| lie suhd cd hp n
somewhat impressive experiment. to prove his dscoyery
he scadcd himself severely, space seven centme
tres broad. all his wrist The application OF the
bicarbonate Immediately relieved the PAIN and II all had
gone well the burn would nave been cured in week
But the Doctor was careless and permitted his cubut
ton TO catch and tear the bstered skin, and further
trouble Of the same sort caused by friction on t1e
edge OF the cuff The result that while the rest OF
the burn was cured, the part thus torn became
troublesome suppuratlng wound. Studying the subject
DR.. Waters thought that possibly vegetable alDumen
might the purpose that animal albumen Is
supposed TO, in the formation OF dermal scales lie pro-
ceeded TO test this theory by removing the scab from
portion OF the wound, drying the surface with bOttng
paper, and then immediately applying the White juice
| OF the common milkweed Aseiepids syrded). Space
after space of the surface was thus treated each
portion being allowed to heal successfully before the
next part was tried According 10 the depth OF the sore
the time OF healing varied from tw enyfour to thrtysiX
bours Int I'm each instance new skin formed completely
across The to this new discovery that
Gently and thoroughly with botfng-paper before apply
ing the mkweed Juice. From the description u appears
that after the juice was applied. and while the healing
was in progress piece OF bOttngpaper was also used
| 10 cover the surface
| THE STRENGTH OF WROUGHT IRoN.-A series
OF experiments has been carried on at the Washington
| Navy Yard by Commander l. A. Beardsee, OF the
limited States Test Board TO ascertain the strength OF
iron used in chain cables II had been suspected win
lust reason that the British Admiralty tables for the
strength Of wrought iron needed revision Not less than
1000 tests OF the tensile strength OF iron have been
made at the Navy Yard, determine the elastic limit,
eopgaton and reduction of OF the various spcci-
mems and fortytwo complete chemical analyses have
also been performed Some OF the conclusions which
| have been reached are remarkable. The Admiralty
tables are declared unsafe and have been pre-
pared The Board finds that the tenacity or two-lnch
| bar for chain cables should be between $4,000 and
40 600 mounds per square inch oneinch bar between
81 900 and 81 900 aud that stronger irons than these
make inferior cables because they have less ducty
| and capacity for welding. The strength OF wrought
IRON and its welding power are Influenced quite as
much by the reduction 1t has undergone in rolling as by
ordinary differences In its chemical composition. In
General the processes for making wrought gave
uncertain quality the product, while the methods OF
making cheap steel confer certainty and uniformity
The ordinary practice OF welding Is capable OF great IN.
provement, by being performed In an atmosphere freed
from oxygen. The Importance or the sulDect VIII nc
conceded since the safety OF human lives must often
depend upon the strength Of ships cable or OF the
| links in bridge chain.
| AN ANCIENT Observation-Disclosures Col
onel Grant OF Hamilton Ontario has discovered re-
Gently Canadian fossil that is OF great interest to
ACKNOWLEDGEMENTS gigantic crustacean Of the genus
Perygotus; maxilIipcd Of abont 32 inches in length
and having twelve dentides In size 1t Is comparable
with the great Hery0otuS dngtiems OF the Scotch
Devonlan rocks but the new species, for which the
name r. canadenSis Is proposed, was of much earlier
geological PERIOD being found in the Niagara limestone
small species OF Pterycotus has been found by PROBES
sor Hall IN the waiCrlmc formation " this State aud
acme fragments OF undcscrbed species In the Clinton
rocks but the present is the first OF the argcg Kind
| ,,or, an enocl, of sucl glca aDtiuuty,