The Men Who Mapped The Skies -- Part 2

On January 1, 1801 an astronomer of Palermo, Italy by the name of Giuseppe Piazzi (1746-1826) noticed a little star like object that seemed to change its position during the next few days. He fell ill and it was several weeks before the news of his observations came to a German mathematician of Gottingen, named Karl Friedrich Gauss (1777-1855) who was interested in the motions of the planets.

From only the first few observations made by Piazzi, Gauss was able to predict the future positions of the moving object. On December 31, 1801 it was found again. It was recognized as a new planet and given the name Ceres, for the goddess of the harvest.

It was the first to be found of a family of almost two thousand unknown and unnamed minor planets or asteroids.

Ceres is the largest, less than five hundred miles in diameter. some very faint ones discovered and in more recent times are only one mile or less in diameter, no bigger than a small mountain. There were, of course, many others found since that time, with not one year passing without even more being found.

Their paths lie mainly between the orbits of Mars and Jupiter, although some of them spill over one side of that track or the other.

A French astronomer, Pierre Simon de Laplace 91749-1827 has been called the Newton of France. He was a brilliant mathematician. In fact, Napoleon gave him a position in the government as a reward for his services to science, but later removed Laplace saying that he had tried to conduct government by mathematics.

Nevertheless, Laplace secured many high honors. He was a member of the Academy of Sciences, president of the French Academy, member of the commission that established the metric system, senator and chancellor.

After the downfall of Napoleon, when the monarchy was restored to France, Laplace was made a marquis. His contributions to science were many. He proved that our solar system is essentially deranged in time, due to its own action.

Laplace showed that any irregularities due to the action of the planets on each other, or to comets, are only temporary, and correct themselves.

Friedrich Wilhelm Bessel (1784-1846) worked at the Prussian king's observatory at Konigsberg. He was the first man to publish a good value for the distance of a start, 61 Cygni. He gave his result in 1838, at about the same time as Friedrich Georg Wilhelm Struve (1793-1864), announced the distance of the star Vega.

In the following year Thomas Henderson 91798-1844), from observations at the Cap of good Hope, announced the distance of the star Alpha Centauri. These star distances were measured by observing the shifts of the stars as the earth revolved around the sun. They are the very shifts that Tycho Brahe and Bradley looked for and oculd not find. Now there could be no doubt that the theory of Copernicus was true.

The positions of Bessel and of Struve were somewhat similar because each was the astronomer for a king. However, whereas the Tsar Nicholas had spent a lavish amount of money on the fine new observatory at Pulkova, the German king spent hardly enough money on Bessel's observatory to keep the instruments in good repair.

It is said that one time the Prussian ruler visited the fine Russian observatory at Pulkova, and as Struve showed him all the instruments he kept exclaiming, "Ah, how fine! If my Bessel could have this to work with!" Upon his return to Konigsberg, he gave Bessel a medal for doing such good work with such inferior instruments!

Not quite one hundred years after the Russian emperor built the fine Pulkova Observatory for F. G. W. Struve, the astronomer's great grandson, Otto Struve, became the director of the Yerkes Observatory of the University of Chicago. A few years later he became director also of the McDonald Observatory of the University of Texas. He was the sixth Struve in four generations to become known as one of the leading astronomers of his time.

The earliest measures of star distances were made visually, with the astronomer's eye at the telescope, making very careful measurements. when photography was applied to this problem in about 1900, the results became much more accurate.

Today, largely through the efforts of an American astronomer, Frank Schlesinger (1871-1943), the distances of thousands of stars are known. First at the Yerkes Observatory, then at Allegheny and last at Yale, Schlesinger set the pattern of the work. Other astronomers all over the world followed his methods and helped to measure the distances of the stars.

At Bonn, Germany, the birthplace of Beethoven, the astronomer Friedrich Wilhelm August Argelander (1799-1875) and his assistants, particularly Eduard Schonfeld (1828-1891), made an impressive visual star map, containing nearly half a million stars.

After that mapping was done by making photographs at frequent intervals to see whether changes have occurred. Photography was quicker and more accurate than the older method of mapping the heavens.

The idea of photographing the stars for making maps of the sky came to astronomers as a result of the great number of stars appearing on the pictures that were made in South Africa of a great comet observed there in 1882.

One of the things Sir Isaac Newton did (in 1665) was to prove that light of different wave-lengths (different colors) is bent by different amounts as it passes through glass or other transparent material.

William Hyde Wollaston (1766-1828) of London and Joseph Fraunhofer (1787-1828), of Munich studied the spectrum of the sun -- the rainbow colored band of light produce when sunlight passes through a glass prism.

They found that there are think dark lines or missing colors in the spectrum.

In 1859, Gustav Robert Kirchhoff (1824-1887), of Heidelberg, explained these lines by showing in the laboratory that each chemical element produces a different set of lines. these lines in the spectrum of the sun or any other gaseous body tell us what the gases of the body are made of.

In this way, we know that the most distant stars contain hydrogen, carbon, nitrogen, oxygen, calcium, iron, etc. These and many other materials known on earth exist in the stars and there is nothing new under the sun, in the sun or beyond it as far as we know.

In Munich, one summer day in 1801, two old houses int he poor part of town fell down. Several people were killed by the accident. there was one survivor, a fourteen year old orphan boy whose name was Joseph Fraunhofer.

He was badly injured but he soon felt that perhaps the accident had not been so bad for him, for a very important man who saw him rescued gave him eighteen ducats, a large sum of money for the time. Part of the money he spent on books and a small machine for grinding pieces of glass into lenses. The rest of the money purchased his freedom from his cruel master, a mirror maker, who had taken the boy in as a helper when his parents had died.

Fraunhofer became one of the most celebrated telescope makers of all time. He taught others to do the same fine work. He and his successors furnished large telescopes to observatories in many countries, including the United States.

Henry Fitz, Jr. (1808-1863) of New York, made his first lens from the thick bottom of a broken drinking glass. Later he made fine telescopes whose mountings were very closely copied from the excellent designs of Fraunhofer.

The work of Henry Fitz was was surpassed by that of Alvan G. Clark (1832-1896) and his brother and his father, a portrait paitner of Cambridge, Massachusetts.

It all began when the brother, George Basseet Clark, at the age of seventeen, was a student at Phillips Academy at Andover, Massachusetts. The dinner bell broke one day and the young Clark, remembering that Newton had made telescope mirrors of bell metal, collected the fragments, melted them into a five inch disc, and started to work.

His father, Alvan Clark, Sr. grew interested, then his bother, who became the best of them all. The largest telescope lens in the world at the time -- the forty-inch objective of the telescope at the Yerkes Observatory on Lake Geneva in Wisconsin was made by Alvan G. Clark and his associates in 1896.

There were many others who would map the skies and improve upon telescopes that would come after these men, however, their stories are for another day in this series of articles.