Milford chronicle., 1910-04-08


travelling as comets do in very elon-
gated e.lipseS, with the sun 10 one Of
the focl. as the attracting point is
called most Of their journey is spent
in slow uneveutuluess far away from
the hearth Of the system-hearth is
just What the word focus means. They
are then small globular aegveEations.
sluggish and dina little rouudish
neba'a in look. such they appear
when first deserted in the telescope
coming in from space for they are
rarely seen az all until they have en-
tered within the orbit Of Mars. Dis
lance IN part, but still more their own
behavior till then. Keeps them hid.
Within this nebuloS.ty. known as the
head, appears as il uears us a bright
/ spot. the nucleus. suddenly there oc-
I ours a complete change in tile deport-
/ ment of fhe body. one which renders
/ it the observed If am observers. aud in
/ less civilized times occasionally its be
[ ing held the harhluger of distress. dis
ease and death.
As soon as the comet gets near
enough the heat of the sun sets up
commotiou within it, BY Nery's deter
miuatlou Of the temperature of the
mblanketed sunward side of the moon
we are enabled 70 infer that this heat
is great az the edrth's distance from
the sun I'm spite of the cold of space.
This temperature is 353 degrees f.
Aud as the comet approaches the
sun this heat must increase inversely
as the square of the distance. At half
the radius of the earth orbit it is al
ready four times as great above abso-
lutte zero, at quarter sixteen times. /
and SO on increasingly the tempera-
ture rising into thousands of degrees.
No wonder the comet acts as il does. /
IL at once becomes uneasy. wakes in /
light and as the specroscope reveals, /
descriptive electric discharges start in |
it which let out the imprisoned gases.
Then begins that spectacular career Of
perihelion passage which makes the
comet so superb an object and for
which 1t pays so dear The gases
which are thus thrust out from the
interior OF the separate meteorites, TO-
gether with such particles Of the iron
as are made gaseous by the heat, fall
prey TO another force besides gravita-
ton This force is the impact Of light
itself. the light emitted by the sun.
That so immateral a thing as a
beam Of light can have power TO move
even pith ball is a conception not
easy TO grasp. Yet there is no doubt
Of the fact Theoretically calculated
years ago 10y Clerk Maxwell from his
electro magnetic theory Of light, for the
gaseous particles proceed to be repealed
by the sun AT enormous speed. each
behaving exactly as il should by math
ematical analysis If such were the Oc-
sasiOning cause. Evidently the light ;
waves have a propellng power in the ,
direction Of their own motion equal !
to their own speed ;
Why, then. is it that the planets be
tray no such effect in spite Of their
size? The answer is. because Of that
very size Gravity acts on the mass
"A matter OF three dimensions; the iSht
force on the surface OF the hody'
-''-N 80
10 size therefore lis SURFACE pears
greater ana greater r'l'o 70 l'S mass .
lniu "hen sH"H enough lne seconu
.olee Is 'ne stronger o. 'H' w Ir
MS Ie'"''''l - "''',, va ~ wy IN l
lue' % ,He TAU ~"
7"SeS' nS'''r ~ "a ~ -, =. /
""'u 9',ie VI me 80 .1e ,.',,,,l-
- . - ~ ll.,o,,I haad 80
- 80 -, ~ 80, or5,,,+ 80
= re -,,, ~, 90, risi,,, ~ /
,artain hoiob+ +boir initial imnotus 1
,,o..or,a tbav fou hack renelied NV /
bo Iiobt waves aItbouob stIl attract
n nv Gravity and are driven out to Il
,orrp tho taii Of tbe comet fresh en- 4
clones taking their place II
Sometimes only single tail is form II
II but at others two or even three are
NOT ont. and when this happens one
: nearly straight. one curved ana one II
-reatlv bent Now. calculation shows II
hat the repelling force in the case Of I
H.. .s,,+ is Courtroom rir,ae rbot Of gray III