190 
NATURE 
[Yuly 1, 1886 
explicit declaration hitherto known in favour of intro- 
ducing such a correction was contained in a letter from 
Kepler to Bernegger of June 30, 1625 (“ Op. Omnia,” t. vi. 
p. 618). It now appears, not only that the conclusion 
was an entirely original one, but that he had arrived at it 
twenty-six years previously. M.Anschiitz promises some 
further elucidations of the point, which we await with 
interest. 
One of the most curious chapters in Kepler’s mental 
history is furnished by his attitude towards the astro- 
logical superstitions of his time. Herwart, as a good 
Catholic, had condemned them ; his correspondent made 
out a case in reply, His contention, it is true, was not 
on behalf of the vulgar charlatanry of the science. ‘This 
he admitted to be indefensible, save on the one poor plea 
of stringent necessity. Providence, as he wrote to 
Maestlin, which had denied to no animal the means of 
preserving its life, had assigned, for that end, astrology to 
the astronomer. He must draw horoscopes and publish 
prophesying calendars, or cease to exist. Thus only could 
he obtain means to pursue nobler studies. The people, 
while giving their money for the lies they loved, uncon- 
sciously promoted the truth they were indifferent to. It 
was an involuntary, but none the less efficacious, “ endow- 
ment of research.” 
So Kepler filled his empty pockets, and satisfied his 
conscience by professing incredulity in his own vaticina- 
tions. They proved, nevertheless, and, as it were, in 
his own despite, highly successful. Not a few of 
them stumbled felicitously into fulfilment. Some art, 
or luck, drew them, now and again, into conformity 
with the future. And since, as their author himself re- 
marked, the game is one in which the hits count, but the 
misses are forgotten (“Das Treffen behalt man, das 
Fehlen aber vergisst man”) his reputation as a seer rose 
high, and brought him in the best and only sure part of 
his income. 
There was, however, a recondite species of planetary 
influence believed in by Kepler as part of the eternal 
order of things. By the belief, indeed, his whole career 
of investigation was profoundly influenced; for the effort 
to justify it led him into a track of thought which finally 
conducted him to the Third Law. One of the chief 
points of interest in the present correspondence is that it 
discloses the time and manner of his entrance upon that 
track. “Lift up your ears to listen: Eureka!” he wrote 
to Maestlin, August 29, 1599 ; and to Herwart, August 6, 
he solemnly announced his invention of a “theorema 
jucundum,” in which was concentrated the whole secret 
of the music of the spheres. Already he gives the title 
(“de Harmonia Mundi”), and, to a certain extent, the 
plan, of the great work published twenty years later. It 
was conceived, as we now see with additional clearness, 
less under the influence of sober truth-seeking, than in 
the fervour of illusive speculation. Essentially, it was a 
piece of brilliant extravagance. That the harmonic law 
of periods and distances should have been found as a 
nugget amid such worthless, though shining debris, is 
one of the oddest facts in the history of science. 
The theory of planetary harmonies was struck out by 
Kepler as an adjunct to his peculiar theory of planetary 
aspects. It might in fact be called its dynamical counter- 
part. Geometrical relations of movement were substituted 
in it for geometrical relations of position. The velocities 
of the six planets were, he averred, so connected that, 
were there an inter-planetary medium capable of convey- 
ing audible vibrations, a celestial chord of the sixth and 
fourth would perpetually resound through space. The 
intellectual perception of potential harmonies sufficed, 
however, for the delectation of the rational creatures 
appointed to enjoy them ; while, similarly, the intellectual 
apprehension of “ aspects” affected, primarily, the sentient 
“soul of the world,” and, secondarily, through the varying 
moods thus impressed by the stars, the course of sublunary 
affairs. The third letter to Herwart is mainly filled with 
details of Kepler’s persevering efforts to complete and 
fortify the visionary analogy between astrological aspects 
and musical intervals. 
Yet even here, in this region of intangible speculation, 
his innate respect for facts did not desert him. What 
autobiographical details he left, we owe to his desire to 
compare his life as it was with what, astrologically, it 
ought to have been. And the first of the present letters 
contains a highly curious little bit of self-study, illustrative 
of the depressing effects of “Saturn in sextile with the Sun” 
at the hour of nativity. Here is Kepler described by 
himself, atat. twenty-seven. 
“ A body of no ample proportions, lean and scraggy; a 
mind unaspiring, that is to say, burying itself in literary — 
nooks and crannies, suspicious, timid, tending towards, 
and abiding in difficulties and knotty points ; manners to 
correspond. Sour and sharp flavours, the gnawing of a— 
bone, the devouring of dry bread, form my gustatory 
delights ; my keenest ambulatory joy is to traverse steep 
and rugged paths, to mount hills, to pierce my way across 
dense thorn-brakes. Pleasure in life other than in study 
I neither have nor desire; proffered, I reject. My 
fortune matches my tastes to a hair. Where others might 
abandon hope, I find access to achievement and fame. 
Yet not over spacious; for my advance is continually 
checked, and my circumstances change without mending, 
All my efforts have hitherto met with strenuous resist- 
ance. It may be that social sympathy will ever be 
denied me while I irritate mankind by advocating the 
movement of the earth, while 
“<tanti ponderis orbem 
Obnixa cervice cito per sidera lapsu 
: Meron ; é 5 
Incito, terricolttm contra nitente senatu. 
A. M. CLERKE 
UPLAND AND MEADOW 
Upland and Meadow, a Poaetguissings Chronicle. By 
Charles C. Abbott, M.D. (London: Sampson Low, — 
Marston, Searle, and Rivington, 1886.) 
‘THIS isa very pleasantly written book by an author 
who may be justly regarded as a kind of American 
Gilbert White. We may as well inform our readers at 
once that the district of which the natural history is 
herein chronicled is situated by a little stream which 
empties itself into the River Delaware, and that the 
name, which will appear to English readers somewhat 
difficult of pronunciation, is of Indian origin. There are 
fourteen chapters in the work, and an index which is to 
be strongly commended for its completeness. It is really 
a most important feature in a book of this kind to have a 
good index, and in insisting upon this necessity we ar 
intentionally paying a complimentary tribute to the 
