The Houston daily post. [volume] (Houston, Tex.) 1886-1903, 1895-12-29
KEpLER,s pLANET LAWS.

To the animated 1t must be u matter
IL wonder and perplexity how the dis
lance of the planets from the sun, around
which they are hurled IN their invafi'
able orbits. can be determined with any
sort of accuracy. kepler, who may justly
be considered one Of the greatest astro-
nomical geniuses Of the world, and VINO
f.ourished during the first hal OF the
seventeenth century, established from OBJ
serVation three laws, having been chI'ci
after the discovercr, hepItr La" :,
which, with Sir Isaac Newton s great law
of gravtutlon. may be regarded as we
very keystone OF the theoIelcal ana me-
uhanical astronomy. The third OF these
laws some times, and not inappropriateiy
called the "harmonic law asserts tnat
the squares OF the periodic times or Tue
p.anets are proportional to the CUBES or
their mean) distance from the sun II,
then, we know the distance OF the eatth
from the sun and the periods of the
earth and the other planets, We are abe
by means Of this remarkable proportion TO
find easily the distance OF the planets
from the sun. Con- equenuy, the deter
mination of these distances is based upon
the distance of the earth from the sum
which is called the ''Rstrononicai hhlt,
We here reltniate that by the planet =
periods we understand the times Of their
revolutions about the sun. II must, there
fore. appear very natural That 20 1nIch
Pains has been taken In nXing me a.
tances depend upon it. II IN TINS astro-
nomicnl unit mn error should be iounh,
the planetary distances can easily ne Cor-
rected. for IT, for instance. we nnl
di-tonce 10 he seventy-two Yards. having
hoen rrea surei with n yard stick, thai
afterwar ri IL found to be m Inch too short
a Is NOT ncrpesniy 80 remeasure me ulN-
tance In order 20 find It's true vaiue, ior
nv an epsv calculation we ind the latter
II 10 seventy wards
To Obtain an accurate value ~ the
ea r,h's distance from the srn, which, UNI
IA no end If ne eighteenth century N'N
very poor approxir aticn 70 TIE correc,
one ast RI no,ners have devised greh'
rnnv methods OF various degrees ot cN-
cellence, II is necessary 10 renear herN
tbut the distance NJ celestial NOW from
the earth is found bv ~ ans or the lat-
,er's radius and the paral,sH,ic ang'e IN, IN,
,ha bod, in n,,eefInn The rrobl0'n o'
and,nr the solar d'stHnre reduces itseU,
therefore to that Of finding the narsileN
az the sun We can not rnionauV nc y
nat.ted 10 enter into the dinerent mon
dds some n which are q wonderfnl ~.
geruItv and we conflne ourselves 10 tf,o
renark thst the vriIe NJ NnN seconn- l1
I'VE meet accurate thus far obtained IT,
which the dis'ar,sceo 90 ~ 20 nc n vt =, &c nv
y means ir,rrohobio thsi with stin In1re
ir,rrovcd methods still more accurate
,,el,ie viii he calculated, thorgh II sHarrtiN
ol,,,its of doubt that the ahnNe Vf'ir y y
go, close annrovinatio OF the true one,
~, aaanr actjun with this subject We mus
~. omit IA mention that the transi'r or
No r,enet Venus across ire suns IT,
have hcen utilized I'm connuilng thr sni
,sraI,rx The last NJ these iranSltt VOC,
v, " 're.cenhar q 1852 and the next WI
,,nt occur before January $, sF4. 20 tnet
~ coming century will he deprived OF
,bjs Interesting phenomenon
'"'7
~. la y "A