The sun., 1893-02-12

: Na tne geometry OF Descartes' foun
guy 'or himself . methoa OF innnit
sss ., anu peean the invention o, nuhion'
, 49,. o "os oINen from oanose , W vi
nnu. Nnie staying ~ his Wv, ,,'a.
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srr ~ tha aa.,.o.'.s .,'s ~ rhi,s io,,,
and bis oh,.sn... liz. .,io, N. H. =
AZ tbia t,n,s ,nusn.as ~. nss.n sa,tan. 7,
1870 ba 49,, a. ,s.a.,s ,rort;n, ,n Al
Ienco Tho a., 49,, =, III. ,rorL ,va. nrh
lisbed IN 1897 a "a 81. ,n, .to odi,ion In ~
In tbe vsar Ie7o yhan Novton was hnt az
vears old bo1,ad .,roadv occom nIIsbed enouct
for tho ,ife vort n, ono r,on, He Ind discoy
ered tho natnro - ,rb,,.. nrbt and ,ho trr,
doctrine Of color. and ba had inyonted Tho III
fercntial caIc,,ins iio hod acbieved o,ho,
| memorable tbinga srob Tor instonco nj tbo
| b,non,,oI tbaor.r th. roaoo,ing toiosoonn
| and the se,tant nh. moeterniece remoins
| upmentioned. the acbievemont wherebv Nav.
| ton towars hon II nd sbou,dore ovor pot onlv nj,
OF his contem poraries lut over every scientiOc
| man who has aver liyed. in a vav for which wa
| can f1nd no parallel In otber departmente n,
| human activity twas IN the year named
(1e72) that Newton heard Of the careful do.
| termination Of the length OF n depree-in otber
words, Of the size OF the earth-vhich had
been made by Picard. near Paris. rb.
| length of the depree turned out TO be
| not sixty miles. but nearly eeventy miles.
| Armed with this now. fact, Newton turned
| back to his old speculation concerning gravity.
| He had worked out the mechanics OF the
solar system on a certain hypothesis. but 1t
had remained n hypothesis somewhat out OF
| harmony with apparent fact. He took out his
old papers and began again tho calculation
II gravity were the forca keeping the loon in
its orbit. II would fall toward the earth sixteen
feet every minute. How far did It fall2 The
newly known size OF the earth would modify
tho figures; with intense excitement Newton
ran through them. his mind leaping before his
hand. and as he perceived the answer to be
coming out right. all the scope and meaning
OF his discovery came with binding flash
upon him. Hecould no longer see the paper:
he threw down the pen: tho secret OF tho uni
verse was to one man at least revealed.
But. OF course. the proof had to be worked
out. Tho meaning OF the discovery might
flash upon Newton. but the demonstration Of 1t
in detail required years to elaborate. For two
years he devoted himself solely to this one OBJ
ject. During that time he lived but to calcu-
late and think. and the most ludicrous stories
are told concerning his entire absorption and
inattent1on TO ordinary affairs or life,' 1t was
by this continuous application that the Prin-
cipin was accomplished. and 1t may be that
nothing OF tho first magnitude can be achieved
withouta like absorbed unconsclousness and
freedom from interruption. But. though de-
sitable and essential for the work. 1t was a SO.
we're tax upon tho powers OF the man. There
Is. In iact no doubt that Nowton's brain suf-
Tered temporary alteration after this effort
The attack was slight, and 1t has been denied.
but there are letters extant which are inexplic-
able upon any other hypothesis. Tho de-
rangement was. however. slight As we'll as
temporary and 1t Is only instructive asshow-
ing at what cost such work as tho Principia
must be produced.
What is the law OF gravitation2 1t Is. OF
course. that every particle OF matter attracts
every other particle OF matter with force
proportional to the mass OF 1t and to the in
verse square of tho distance between them.
Tho following are some OF Newton's deduc-
tions from this law: In tho first place. by
knowing tho length OF the year and the dis
tance OF any planet from the sun. the suns
mass can be calculated In terms of thht Of the /
earth. 80: too. the mass OF any planet possess
ing satellite can be computed. Again. since
the moon Ia attracted not only by the earth.
but BY the sun also. its orbit is perturbed.
and Newton calculated out the chief OF
these perturbations AS. moreover. each
planet is attracted not only by the sum-
but by the other planets. their orbits
are slightly affected by each other. It was
Newton who began the theory Of planetary
perturbations. He also recognized comets
ns members OF the solar system obedient
to the same law OF gravity and moving in