Part 19 (1/2)
From these notes, taken on the spot, it is evident that the contemplation of a total eclipse of the Sun is one of the most marvelous spectacles that can be admired upon our planet
Some persons assuredrapidly over the landscape My attention was otherwise occupied, and I was unable to verify this interesting observation The shadow of the Moon in effect took only eleven minutes (347 PM to 358 PM) to traverse the Iberian Peninsula from Porto to Alicante, _ie_, a distance of 766 kiloround at a velocity of sixty-nine kiloher than that of a bullet It can easily be watched from afar, on the mountains
Some weeks previous to this fine eclipse, when I infor which it could be observed, I had invited theht witness, including the effects produced by the eclipse upon animals Birds returned hurriedly to their nests, ss lost thees were hypnotized, frogs croaked as if it were night, fowls took refuge in the hen-house, and cocks crowed, bats caathered under their s howled, others crept shi+vering to their rasshoppers chirped as at sunset, pigeons sank to the ground, a swarm of bees went silently back to their hive, and so on
These creatures behaved as though the night had cons of fear, surprise, even of terror, differing only ”in degree”
frorandiose phenohtened by a scientific education
At Madrid the eclipse was only partial The young King of Spain, Alfonso XIII, took care to photograph it, and I offer the photograph to n did ive it me a few days after the eclipse
[Illustration: FIG 79--The Eclipse of May 28, 1900, as photographed by King Alfonso XIII, at Madrid]
The technical results of these observations of solar eclipses relate rand problem of the physical constitution of the Sun We alluded to thereat total eclipses have been of immense value to science
The eclipses of the Moon are less i, than the eclipses of the Sun Yet their aspect lected on this account, and it , our satellite does not disappear entirely in the Earth's cone of shadow; the solar rays are refracted round our globe by our atlobe with a rosy tint that reminds one of the sunset So doubtless to lack of transparency in the atmosphere, and the Moon becomes invisible This happened recently, on April 11, 1903
For any spot, eclipses of the Moon are incomparably more frequent than eclipses of the Sun, because the cone of lunar shadow that produces the solar eclipses is not very broad at its contact with the surface of the globe (10, 20, 30, 50, 100 kilo to the distance of the Moon), whereas all the countries of the Earth for which the Moon is above the horizon at the hour of the lunar eclipse are able to see it
It is at all tihts to the Heavens, and I strongly advise o it
CHAPTER XI
ON METHODS
HOW CELESTIAL DISTANCES ARE DETERMINED, AND HOW THE SUN IS WEIGHED
I will not do my readers the injustice to suppose that they will be alarmed at the title of this Lesson, and that they do not employ some ”method” in their own lives I even assuh to take me on faith when I have spoken of the distances of the Sun and Moon, and Stars, or of the weight of bodies at the surface of Mars, they retain some curiosity as to how the astrono as it is useful to co state these bold conclusions
The Sun seems to touch the Earth when it disappears in the purple ht: an io hand in hand down the constellated sky; and yet one can not think of their inconceivable distance without a shi+ver
Our neighbor, Moon, floats in space, a stone's throw from us: but without calculation we should never know the distance, which remains an impassable desert to us
The best educated persons sometimes find it difficult to admit that these distances of Sun and Moon are better determined and more precise than those of certain points on our ive an exact account of thethem
The calculation of these distances is ulation_” This process is the same that surveyors use in thevery alar about it If the word repels us a little at first, it is from its appearance only
When the distance of an object is unknown, the onlyits apparent size is by le which it subtends before our eyes
We all know that an object appears smaller, in proposition with its distance froeometric, and proportional to the distance Every object rele of 1 degree, whatever its real dimensions Thus a sphere 1 ree, if we see it at a distance of 57180 ree, if distant 57 tiht, that is to say, at 10260 meters A sheet of paper, size 1 decinitude
In length, a degree is the 57th part of the radius of a circle, _ie_, from the circule is expressed in parts of the circuree? It is the 360th part of any circuree is a centimeter, seen from the center of the table Trace on a sheet of paper a circle 0360 ree is a milliles]