New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1878-04-06
SCIENCE FOR THE PEOPLE.

To TELL TINE BY THE SUN.-The 10th Of
this month if the sky clear at may be OF scrvic'
10 people who set their watches by the suu for NJ ina
hour the real time and the ordinary clock time viii dihe
By less tina two seconds. The coincidence only occurs
four times in the year. To be more exact III the STATE
ment as to the 18th inst. the sun at noon that day
crosses the meridian 1S2 second ahead OF local time
with sun dial that is correctly person can ther
set his watch accurately; and conversely bis watch
right he can then place sun-dal properly In the alb
sence OF such an instrument he can make substitute
for a suu.dial by permanently fixing in Horizontal
board T-,quarc with one leg upright Tie support o.
the board should be levci,d with spirit level The
correctness of the setting Of the Tsquae can be aseer
tanned by comparing the upright leg with plumb ime
This apparatus bcug prepared beforehand the 18Th
Inst at about two seconds before II O'Clock the board
TO be so placed hat the shadow OF the upright leg Will
fall exactly on the horizontal leg II both parts OF the
square arc OF equal thickness there will be little d
cuty IN such performance. all that is neediu 10
observe IL that there u no stdHuW tH.oWn Vl I -
Of the horizontal leg The board ~ 10 nc fastener per
manenty Ia the position attained az that moment on the
10th inst Probably IL would be best 10 quinn. c pu',
ton OF the board upon IT'S support, at We the, hla
noon, any day, when The uplGht leT IN tno sunsu
casts no side shadow. The difference between Io moon
and common time Is furnished hy THE Tribune Aldhae
for every day In the year
CLAIMS OF PRIOR DIsCovERY.-SOme Eng
lishmen have just found that the late Professor
Wheastone invented the telephone more than quarter
OF a century AGO, and that he described and exhibited
the instrument It does appear however, that he
transmitted speech by IT, claimed ;hlt il bad such
capacity Probably the British public is FESTIVE under
the high prices charged for telephones by their inventor
and patentee At recent meeting OF the French Acad-
omy OF Sciences, NJ Charles eros claimed that he had
described the phonoguph In q sealed document hled
April 80 1877, and opened at public meeting ON Dcccm
Der g. lie says that his photograph gave the same re
suits and employed the same the instrument
Mr. Edison claims TO have invented. such statements
are ominous OF awsuts m the future.
THEORIES OF THE SUNS HEAT.-As yet no
perfectly satisfactory basis has been found for theory
OF the suns heat which shall be quite IN accordance with
accepted hypothesis Of the earth's formation. The con-
traction Of the suns Is estimated giving ont heat
for only 20OOOOO0 years, while the slrauacaOn Of the
earths crust may have taken twenty-five times that pc
Rod Professor Cro has devised theory which de-
scribed in these columns months ago. designed TO
meet the difficulty. lie shows that the period OF the
suns heat may havo been immensely longer. If We sup
pose that that uminary originally two separate
bodies travelling through space at velocity Of 500.
900 or 1880 miles per second and that these bodies
came into collision. Professor Daniel Krkwood. re-
viewing DR. CroIrs hypothesis considers II unsitsiac-
tory because II has sufficient basis In the facts OF OBJ
scryation. We have no knowledge OF more rapid mo-
ton than 200 miles per second among the stars and the
chances OF collision remotely improbable. On the
whole II seems 10 the Professor more difficult q grant
the demands Of Dr. Crol's hypothesis than 20 believe
that IN former the qualification Of the earth pro-
ceedod more rapidly than now But Professor Kkwood
j. astronomer, and Il Il not particularly surprising
that ne prefers 10 put the burden the shoulders NJ the
biologists, thai he less readily conceive OF
change IN the method OF dong things IN the sky than on
the earth.
RAsCALITY IN House, UILDING.-An instance
is related 1he Thunder and Sanitary Engineer, which
somewhat surpases the ordinary experience Of our ct
in the frauds Of house construction The occupants
OF one Of a OF brick dwellings IN Brooklyn COM
planned OF bad odors In the house. which had been
Gently built, and contained the sOcalled modera I'm
provcmcnts. On examining the plumbing, IL was found
that the trap short make ont with the soh
ppc and the connection had been effected By means Of
short carryingpicce which was open the upper side.
and consequently permitted the free escape into the
house OF the gases from the piIe. But more cNtraOr
binary discovery soon followed Behind the pipe aud
touching IT, was the furnace uc OF the adjoining house.
From the cellar to the second story there was clear
opening in party wall between the houses and In
this space the tin hue u one and the waste pipe ~ the
other inserted The pipe. heated by the duc Of
would be difficult 10 devise construction more apt 10
cause or communicate DIRE between dwellings
EXPERIMENTS WITH FLOATING MAGNETs.-
Professor A. NJ. MAYER describes IN The American Jour
nal Of Science and Arts, entertaining aud easily
performed experiments IN magnetism. Several sewing
needles of No or sza. iil, Liza
y
passed into small cork that Will just float Il upright;
the corks may he d inch long and aIS inch across
The eve OF the needle should barely be above the surface
Of the cork Three four more OF these needles are
thus 10 be oated in basin OF water and the n pole Of
large cylindrical magnet to be brought down over them
They will Immediately take geomerical positions, tho
figure formed being smallest when the magnet above u
broughtmost closely to them Three needles thus take
position at the points Of equaieral trangici four
form a square, or a triangle with In tho centre; Ave
form pcnagOu, square with one In the centre FIX
form pentagOn with one In the centre or triangle Of
three side. Professor Mayer has obtained regular
figures up to combination OF twenty needles. Some OF
the forms stable the needles may DC sent OUT o tue
unstable into the stable forms by vibration Inc EXPERT
ncns may he varied To any extent by tt use OF two
more magnets inducing separate combinations Inc
figures peculiarly suggestive OF molecular aetlnn anu
aggregation and may bc shown 10 great advantage "
means OF II vertical magic lantern
THE CULTIVATION OF MUSHROOMS. - The
japanese raise mushrooms ON dccaYcd roots stumpso or
logs Certain OF the oak tree when cut down,
furnish the most acceptable mushrooms llcisons are
cut through the bark OF Tao logs, which are made
by splitting trunk into quarters. The logs are left in
the forest to rot Cor about three years when mushrooms
grow upon them " the rotten portion OF the wood be
scraped away After the first crop II removed, tho logs
are nut IN the morning and In the afternoon
are beaten with mallet; they then ranged end,
slantlng IN the forest and the mushrooms grow again
upon them This process 10 continuously repeated and
II s fornd that the largest mushrooms grow upon the
logs that beaten hardest. Another method OF culture
consists burynE the logs The japanese dry their mus
by artificial beat, slowly and carefully applied.
The industry ~ Of some magnitude aud considerable
portion Of the dried products exported.
Zo0LOGY BY TIE SFA-sHORE.-Tho study of
tho animal forms in the waters OF has grown
in popularity very rapidly. Mr. J. H. Emertol, OF Salem
Mass. and Mr. 9. g. MinOt, Of Boston, announce that
they will open June J. Marine Geological Iabora-
tory Salem Neck for the OF students of this branch
of natural history The laboratory is suitably equipped
The experience OF Mr. Emerton with the United States
Fish Commission, well as in the Agassiz Museum
especially fits him for this enterprise Every year brings
an addition TO the number OF naturaliss who find tho
REQUISITE combination OF recreation with work. by trans