Part 3 (1/2)

relating to central forces other than the force of gravity, which are or may be concerned in the construction of the sidereal heavens This early idea was still entertained by HERSCHEL in 1789, and the mathematical papers referred to must be contained in the _Minutes_ of the Society, which on its dissolution were torn from the Minute-book and returned to the writers

The earliest published writing of HERSCHEL is the answer to the prize question in the ”Ladies' Diary” for 1779, proposed by the celebrated LANDEN, naht of a iven, it is required to find how iven weight is fastened to its middle and vibrates with it”

In the _Philosophical Transactions_ of the Royal Society for 1780, are two papers of his The title of the first is, _Astronomical Observations on the Periodical Star in Collo Ceti_, by Mr WILLIAM HERSCHEL, of Bath

This was communicated to the Society by Dr WILLIAM WATSON, Jr, and was read May 11, 1780, at the same time as the other paper on the mountains of the moon It is to be noted that HERSCHEL was at this time plain ”Mr WILLIAM HERSCHEL, of Bath” It was only in 1786 that he becaree of LLD

Neither of these two papers is specially remarkable on its purely astronomical side The problems examined were such as lay open before all, and the treatested

The second of these two contained, however, a short description of his Newtonian telescope, and he speaks of it with a just pride: ”I believe that for distinctness of vision this instrument is perhaps equal to any that was everobtained excellence in theof his instruments

In his next paper, however, read January 11, 1781, a subject is approached which shows a different kind of thought It is the first obvious proof of the truth of the state afterwards (1811), when he said: ”A knowledge of the construction of the heavens has always been the ultimate object of my observations”

The title of this paper was _Astronomical Observations on the Rotation of the Planets round their Axes, made with a view to determine whether the Earth's diurnal motion is perfectly equable_ Here the question is a difficult and a remote one, and the method adopted for its solution is perfectly suitable in principle Itupon their results In practical astronoiven, but also careful estimates of the errors to be feared in them, and a discussion of the sources of such errors The same volume of the _Philosophical Transactions_ which contains this paper, also contains another, _Account of a Comet_, read April 26, 1781 This comet was the iuht of Tuesday, March 13, 1781 ”In exahborhood of H _Geer than the rest; being struck with its uncommon appearance, I compared it to H _Gea_ and _Geer than either of them, I suspected it to be a comet” The ”comet” was observed over all Europe Itsobt was computed by various astronomers, and its distance from the sun was found to be nineteen times that of our earth This was no comet, but a new major planet The discovery of the a since the invention of the telescope It had absolutely no parallel, for every other major planet had been known from time immemorial[13]

The effect of the discoveries of GALILEO was felt almost more in the moral than in the scientific world The mystic number of the planets was broken up by the introduction of four satellites to _Jupiter_ That _Venus_ emulated the phases of our moon, overthrew superstition and seated the Copernican theory firmly The discovery of ”an innumerable multitude of fixed stars” in the Milky Way confounded the received ideas This was the great mission of the telescope in GALILEO'S hands

The epoch of an with the detection of the large satellite of _Saturn_ by HUYGHENS, in 1655 Even then superstition was not dead HUYGHENS did not search for more moons, because by that discovery he had raised the number of known satellites to six,[14] and because these, with the six planets, made ”the perfect number twelve”

Fro about _Saturn_ Since 1684 no new body had been added to the solar systeht coland, the remarkable discoveries of BRADLEY (1727-62) had been in the field of practical astronomy, and his example had set the key-note for further researches France was just about beginning the brilliant period of her discoveries in matheations like HERSCHEL'S, with the possible exception of DARQUIER'S and FLAUGERGUES' The observatories of SCHROETER and VON HAHN, in Germany, were not yet active The field which HERSCHEL was created to fill was vacant, the whole world over It was especially so in England The Royal Observatory at Greenwich, under MASKELYNE, a skilful observer, whose as mostly confined to meridian observations, was no rival to a private observatory like HERSCHEL'S The private observatories the, at Kew, of Dr WILSON, at Glasgow, of Mr AUBERT, at Loa perhaps the most important

The whole field was open What was perhapsHERSCHEL'S lifetime, no astronomer, public or private, whose talents, even as an observer, lay in the same direction

It hardly need be said that as a philosopher in his science, he had then no rival, as he has had none since His only associates even, were MIChell and WILSON[15]

Without depreciating the abilities of the astronoland, his cotereat roup of se effected in the state of astronoland but in the whole world, simply by the discovery of _Uranus_ Suppose, for example, that the last planet in our systeone on In spite of one and another difficulty, he would have made his ten-foot, his twenty-foot telescopes His forty-foot would never have been built, and the two satellites which he found with it ht not have been discovered Certainly _Mimas_ would not have been His researches on the construction of the heavens would have been made; those were in his brain, and must have been ultimated The mass of observations of _Saturn_, of _Jupiter_, of _Mars_, of _Venus_, would have been made and published The researches on the sun, on the ”invisible rays” of heat, on coht have been one into the _Philosophical Transactions_ as the work of an amateur astronomer, ”Mr HERSCHEL, of Bath” They would have been praised, and they would have been doubted It would have taken a whole generation to have appreciated them They would have been severely tried, entirely on their merits, and finally they would have stood where they stand to-day--unrivalled But through what increased labors these successes would have been gained! It is not , the subsidies for the forty-foot telescope (4,000), the co It is more than this It would have been necessary for him to have created the audience to which he appealed, and to have conquered the most persistent of enemies--indifference

Certainly, if HERSCHEL'S mind had been other than it was, the discovery of _Uranus_, which brought him honors froave hiht have had a hurtful effect But, as he was, there was nothing which could have aided his careerdiscovery It was needed for hi a free play to a profoundly philosophicalthe vacant spaces beyond _Saturn_

His opportunities would have been profoundly h his personal worth would have been the same

”The Star that froh it be to half the earth, Though half a sphere be conscious of its brightness, Is yet of no diviner origin, No purer essence, than the One that burns Like an untended watchfire, on the ridge Of so, like twinkling winter la the branches of the leafless trees”

To sho completely unknown the private astronomer of Bath was at this time, I transcribe a sentence from BODE'S account of the discovery of _Uranus_

”In the _Gazette Litteraire_ of June, 1781, this worthy man is called MERSTHEL; in JULIUS' _Journal Encyclopedique_, HERTSCHEL; in a letter from Mr MASKELYNE to M MESSIER, HERTHEL; in another letter of MASKELYNE'S to Herr MAYER, at Mannheim, HERRSChell; M

DARQUIER calls him HERMSTEL What may his name be? He must have been born a _Ger continue The news spread quickly from fashi+onable Bath to London On the 6th of December, 1781, HERSCHEL was elected a Fellow of the Royal Society, to which he was formally ”admitted” May 30, 1782 He was forty-three years old

He also received the Copley ular star”[17]