New-York tribune., 1878-12-21
SCIENCE FOR THE PEOPLE

on the principle that heat is kind Of vibration or mo-
the molecules OF matter and that It ay be pro
duced by mechanical means such as the rubbing o Two
sticks together. the hammering OF irou Mr. Chelew
Of illinois, set TO work to devise machine that shonld
produce heat without fuel His thermachon as he wishes
his machine called, Is said by correspondent OF
The Peoria Q Transcript to be success ut consists
he wres OF "paln wooden box about two feet square
high; and attached to one SIDE, Ike an
addition, Is box made out OF thin boer-piae' Delng
the height and width as the wooden poI' ana
about foot deep; in the wooden box Is the mouVe
power in the iron box the heat is generated Ihe es-
sentia part OF the heatproducing apparatus Is pate
which Mr.. Chelew calls model plate MI CheieW
requested me TO insert small wire through sIhah
hole in the iron box after previously starting the "oIA
In few seconds / withdrew the wre and II was TOO
hot to touch with the hands; he then took small un
cup Of cold water and put in the Iron DOx III Two OF
three minutes he Withdrew 1t boiling not vi course
Is as yet very imperfect, being deficient III many det1s
The highest degree OF heat attained with 1t Is about
250o. But Mr. Cheew expects that when certain liI
to show 5000 degrees heat or perhaps higher, ana
with other improvements and discoveries, TO generate
neat to any required degree The same llstuneut VIII
produce a higd or low degree of neat may be re,
quire1, which viii be contr0llea Dy 'lesmator.
There Of course, be little dIfculy VI producing
heat by simple mechanical out 1t Is very mpIoD-
able that 1t can be produced eeonGmieaIy' On th's
point the correspondent Is slgln 'anlly sliehI
GETTING RID OF RATs.-A correspondent OF
The English Meeaanie gives two valuable hints
for riddng premises of rats. One very good plan lie
says. to nail red herring on the wall Of the ware
house place infested about eighteen inches from the
floor; this little 10 one side beneath the nsh place
brick piece of wood near the wall AT an equal dis
tance the other side set ordinary steel snapuaD
not bated. The rats, IN jumping of from the brick to
at the herring after few attempts are sure U fall
down in the trap. This good permanent plan as II
is somewhat above their comprehension. If rats have
undermined the foundation walls, which they do some
times 10 such extent to endanglr the building,
is OF To attempt 10 stop them out by tampnG their
burrows WITH broken glass bottles for they work dill
gently to make fresh better way is 10 put
shOVeltu OF dry nd over every hole. IN" rats soon
come up through this hui ia so doing let ha!f me sand
into the hurrow, which, unlike eafh ihey cannot either
force or carry up again. ana by rel eatnS ms a. every
fresh-opencd place toor runs become qnl'e hled up
and tney maze up your Foundations aEaln l3y tins
means have known Il clanary That was terribly in-
tested with quite cleared OF them. All their burrows
being at last filled with sand they compelled to be-
take themselves elsewhere
FALLS OF ST. ANTHONY AND MINNEHAHA.-
Biologists OF hign character General o. h Warren,
IN The american Joi'd Of Science and Arts, have es
tImated tue age Of the gorge Niagara Falls on the
present rates OF recession and, though the result
certain 1t indicates the origin 10 be IN recent geological
times, although anledatlng the historical In ,mi-
lar way the time required by the Mississippi 10 cut he
gorge from Fort Smelling TO the Falls OF ST. Anthony has
been calculated by Professor A. H. wlrcne. on data
ears, iN dNSllill-
ing that the forces in producing ths result have
maned uniform during this period Since the Falls Of
ST. Anthony were at the junction Of Munehaha Creek
they have recedcd six ana quarter miles Tue Mime
haha Falls since tLat ne have recedcd three-lfths OF
mile Both streams have cut into the formation,
starting with the same height Ol fail. The-e relative
rates nave been about 10 TO- The proportion Of the
volumes Of the two streams, Judging by their present
drainage areas. is about u miles 20 y 500
square miles, or about IL 10 300 That Is To siy the
recession OF the Mlnnehaha Fails has been thry nrs
lhstcf tham would nave been n prnportioncd 10 the
Noume. Ihls may be accounted Tor by The greater
mOspherc inlGcnce OF the smaller falls. which, cNamt-
nation shows, keeps ahead OF tue effect o. the water,
forming cave under the iall 10y the dropping down Of
material which the water then washes away. At the
greater fails the volume Of water almost constantly pro-
tects the rocks from the action OF the Hence
we must give very considerable influence 10 the opcr-
aons OF tue atmosphere In aiding tue erOsions of small
streams and ~ demollshlng ellis where the water can
remove the doTis.
KEEPING Down THE CARPET BUG.-Dr H.
A. Hagen. of Cambridge IN interesting communica-
ton 10 the Boston Society OF Natural History on The
Carpet Beetle aud Other House and Museum Pests"
gave some practical hints for destroying the carpet
bug, which has spread Rapidly localities
during the past few Acting the theory that
prevention Is better than cure think say, the Doctor
the best 10 be followed would be first 10 prevent
the entrance OF the insect Therefore, every carpet
and rug should be considered dangerous and treated
as the old ones that Is, exposed In the open air.
and strongly beaten before laid IN the The
custom, 10 order carpets in the and lay
them directly In the rooms ID apparently the most dan
gerOus be pursued. Further observed
that the beetles by preference follow the cracks In the
floor, all should he made tight, at least filed with tai
low. The talOw is dangerous substance for the
larve and eagerly avoided by Them the fat easily
taches the spiracles with killing effect. Therefore
the most common candle taOw being softer, il better
than the purified. For the same purpose. sh 'uld
taowei paper to be put aOng the walls,
only foot or two underneath the carpets, Just the
places near the walls are their most chosen abode. or
course careful m ana more IRE MiregnGm inspection OF the
TO be in any way alarming think Il w be Impossible
be TO keep them within limits so that they Will be not
more dangerous than any other house pest"
A NEW MICRoPHoSE.-A late number of
The Electrician contains description of a new micro
phone, invented by NJ. Trouvo which to possess
several advantages the ordinary form OF that In
srumen The apparatus has the appearance OF dark
lantern, the candle OF which s replaced by stick of
carbon II consists Of two discs OF carbon between
winch carbon pencil, pointed at both ends plays
loosely In small cavities. The whole Is inciosed in a
kind Of lantern, and thus constructed the microphone
may be carried in the pocket without injury; It's sensi
by Is augmented and II is extremely convenient for
many experiments II the instrument placed upon "A
watch the ticking is reproduced at distance by the
telephone together with the sound OF talking the noise
OF footsteps the slightest vibration OF the table due
10 any contact with It, II the mcrOphone suspended
by the conducting wires. 1t Is extremely sensitive 10 at
Vibrations, reproducing words spoken at
Of twenty-five yards from the micrOphOne
the other hand, the ticking OF the watch placed
upon the stand, or slight contacts with the table on
winch the latter is placed scarcely heard IN the dis
tant telephone. Thus suspended In the middle OF an
apartment the nicrophone reveals all its secrets the
timbre OF being perfect though two tee-
phones used. Whether the instrument be sus-
pended not, tho sounds produced by any insect I'M
prlsoned within 1t are magnined and reproduced In
another form the instrument the discs Of carbon
a anm the