The Surmise of Vulcan

Since the invention of the telescope in the early 1600's several major planets have been discovered in the remote regions of interplanetary space beyond the

realm of Saturn, namely Uranus, Neptune, and Pluto. The search for more such planets has continued to some extent even to this day. In the last century, although, a

flurry of serious speculations were circulating among world class astronomers about the possible existence of a planet not at the outer reaches of the Solar system but

at the inner region of the planetary family, inside the orbit of Mercury. This suspected planet precipitated the exploration of the Sun's immediate neighborhood

resulting in a number of cases where observers have reported such a body.

At one time it was believed that there was a planet even closer to the Sun than Mercury based on unexplained orbital perturbances observed in the latter

caused by the gravitational influence of a supposed heretofore undiscovered object hidden in the Solar glare. It was already known that the point of planet Mercury's

orbit closest to the Sun was progressively 38 seconds per century greater than would be predicted on the basis of Newtonian mechanics. In 1845 a French

astronomer by the name of Urbain Le Verrier (1811-1877), attempted to resolve this problem by proposing the existence of a planet lying inside the orbit of

Mercury which he named Vulcan, after the Roman god of fire and the blacksmith of the gods. Subsequently he began to look for it. Previously he had made

extensive mathematical studies on the motions and variations in planetary orbits and became an expert on the subject in his own right. His confidence was such that

he named his planet before he ever found it. Consequently, Le Verrier was delighted when, in 1859, he received a report from an amateur astronomer by the name

of Dr. Lescarbault, a country physician, who lived in the small town of Orgenes, some 80 miles from Paris. Dr. Lescarbault, who had read some of Le Verrier's

published work, claimed he had actually watched the passage of such an object crossing the solar disk on the 26th of March, so Le Verrier made haste to go and

see him. It must have been a strange meeting. By this time Le Verrier was director of the Paris Observatory and internationally famous as a co-discoverer of

Neptune. He is said to have been such a rude man that he was once forced to resign his post which he returned to later upon the death of his successor in a boating

accident. Lescarbault, on the other hand, was intensely shy, and very much of a novice. He was the local Doctor but also a carpenter and he would work out his

calculations on planks of wood planing them off when he had no further use for them and to make room for new ones. His equipment included instruments rough and

home made but singularly accurate. His clock was a simple pendulum, consisting of an ivory ball suspended from a nail by a silk thread. His observations were

recorded on prescription paper, covered with grease and laudanum. Based on the doctor's evidence and satisfied as to the genuineness of this enthusiastic observer's

work Le Verrier congratulated and honored him as the "discoverer" of Vulcan, and "confirmed" the discovery. He calculated that Vulcan was an object 1,000 miles

in diameter giving it an apparent diameter from Earth of about three arc seconds, occupying an orbit 18 1/2 million miles from the Sun with a revolution period of 33

days, and an orbit inclined 12 degrees to the ecliptic. Vulcan was later even given the sign of a hammer as a legitimate planetary symbol. Other observers had, at

various times, seen spots of a planetary character rapidly cross the disk of the Sun although the observation of Lescarbault turned out to be the most remarkable

since it seemed to justify the theoretical conclusions of Le Verrier. After he analyzed all the observations of this sort that he could find, which numbered about 50,

and calculated