Imagini ale paginilor
[blocks in formation]

FREQUENTLY passing through Bedford to his seat at Colworth, and attending the local assizes as a county magistrate, Dr. Lee was wont to favour me with occasional visits; and, having always been an ardent admirer of Urania, he felt the enjoyment of a little practice, as well as the advantage of a good telescope, easy to manage, aud always ready for use. I do not accuse him of violating the tenth commandment, but it was clear that he would not remain much longer without seeking the means of penetrating space. And thus it happened.

In December 1828, soon after I had completed my observatory at Bedford, and mounted the instruments lent by the Astronomical Society for that purpose, it was communicated to me that the telescopes, clock, transit circle, portable transit, and numerous other articles, which had belonged to the late Rev. Lewis Evans, were to be disposed of by private sale. On viewing them, I was rather chagrined at the circumstance not having occurred before my arrangements were carried into effect; especially as the circle seemed to me greatly superior in simplicity and efficiency to Colonel Beaufoy's, with which I had just commenced operations. (See my Cycle of Celestial Objects, vol. i. pp. 333 and 335.) On mentioning this to Dr. Lee in the evening, he resolved to make the purchase, and to present the circle to the Astronomical Society, with the understanding that it was to change places with the one at Bedford; a transaction which accordingly took effect.

This beautiful transit-circle being thus disposed of, there still remained a considerable quantity of instruments with Dr. Lee, of which he shortly afterwards became desirous of making a proper use. On being consulted, I recommended that the small transit-instrument should be mounted on a pedestal in the South portico of Hartwell IIouse, where it would command all the Greenwich stars from the zenith nearly to the horizon; the adjoining strong-room then could be fitted for the clock and other instruments, and the requisite books and catalogues; while a second stone pier was proposed to be erected at a little distance in front of the portico, on which to place the reflecting-telescope. This proposition was adopted, and, with the help of Dr. Lee's staff of domestic artisans, I soon carried it into effect, insomuch that, having approximated the meridian pretty closely, the moon and several stars were observed on the 3rd of April, 1830.

I should here mention that the transit was a portable one, of twenty-four inches in length, on a cast-iron stand, by Carey;* and the reflecting telescope is of five inches and a half aperture, with a focal length of thirty-six inches, having a good finder and several eye-pieces, on a stout brass tripod. The clock was made by Mr. R. K. Barton, of Ramsbury in Wiltshire, and exhibits a capital train of wheel-work to a Graham's dead-beat escapement.

It is fitted with a novel pendulum, expressly made for the Rev. Lewis Evans by his friend Troughton, who had just invented it. In the construction of this ingenious application, the apparent rod is a cylindrical tube of brass, reaching from the bob to the suspension-spring. This contains another tube with five wires inside it, so disposed as to produce three expansions of steel downwards, and two of brass upwards. These lines of wire are so proportioned as to length, that they act inversely upon each other's impulses, and by the combination destroy the effect that either metal would have singly. In this contrivance the estimable artist reasoned well, and the attempt was worthy of him: but it so happens that the main variations by which the instrument is affected are owing to the outer or covering tube, and, even were this removed, it would still be liable to the jumps and irregularities incident to gridiron pendulums. Troughton therefore soon abandoned it as a failure.

* This transit-instrument was afterwards lent to the Euphrates Expedition under Colonel Chesney, and went to the bottom of the river in the ill-fated iron steamer which foundered there in a heavy squall. It was, however, recovered, and restored to Dr. Lee, who has now lent it to Mr. Lassell, of Liverpool, as an aid to his mighty equatorial reflector.

It should be mentioned that the said strong-room, besides being the repository of the fixed instruments, contained also various portable ones, and presented sufficient means for much good work, terrestrial as well as celestial. Of these I may instance the following :

A reflecting circle by Troughton, with counterpoised stand, and an artificial horizon.
A ten-inch brass sextant, by Ramsden.
A five-inch sextant, by Ramsden.
A quadrant of eighteen inches radius, by Nairne, with diagonal graduation.
A quadrant of twelve inches, by Liverton, of Liverpool.
A trough, framed glass, and mercury bottle for artificial horizon.
A seven-inch theodolite, and tripod stand, by Carey.
A small azimuth compass, in a brass box.
A ten-inch surveying compass, with sight vanes and a tripod.
A surveying spirit-level.
A clinometer of six inches radius.
A circular protractor of six inches in diameter.


Hence it will be seen that the little observatory was richly furnished; and it had, moreover, an abundance of lenses, coloured glasses, barometers, thermometers, and hygrometers. There were two or three telescopes, of which the Gregorian already mentioned was the best; but an old one deserves notice for its tolerable performance: it is a vellum eight-drawer “spy-glass” of ten feet in length, having a single object-glass two inches in diameter, made by the celebrated Giuseppe Campani, of Rome. Besides which, in the winter of 1829, when I became possessed of Sir James South's six-inch object-glass, I transferred to Dr. Lee a fine five-foot telescope of three inches and three quarters clear aperture, which had been specially made for me by the elder Tulley; and which proves to be one of the very best of its order. This instrument is powerfully fitted with a range of eye-pieces varying from twenty to eight hundred times,* coloured glasses, adapters, prisms, and micrometer; and, being mounted on a stout equatorial stand, with rack-work motion and all necessary appliances, it formed a powerful addition to the means in hand. The solidity and efficiency of the portable mounting entitle it to notice


Such was the first observatory at Hartwell, which, small as it was, created a desire in Mr. Thomas Dell, of Walton, near Aylesbury, author of the volume of Evening Amusements for 1832, to possess also a clock and transit-room ; and I accordingly, at the request of Dr. Lee, superintended the erection and equipment of one for him. The two establishments were to be worked in emulation of each other; but scarcely had the good Doctor conquered the difliculty of watching the stars across the wires while transiting, than he yearned for more power, and consequently a larger sphere of utility in the Uranian cause. His Alma Mater had instilled the physical theory of astronomy into his mind, and practice brought the conviction of its, so to say, tangible advantages.

* In mentioning the whole range of eye-pieces, I should remind a beginner that the working ones are those which magnify from seventy-four to two hundred and sixty-two times, as severally marked on them. The higher powers are merely for extreme experiment.

While thus we penetrate ethereal space,

And Heav'n's wide expanse so minutely scan,
God's wisdom, pow’r, and handiwork we trace-

The noblest study of aspiring Man.
New systems open to us as we climb;

Each glittering star gives law to circling spheres,
Which run eternal rounds in faithful time,

Nor err one moment in ten thousand years !
Perpetual motion Heav’n’s high works maintain,
So often sought on earth, but ever sought in vain.

Besides contemplating the admirable balance and beautiful arrangement of the starry firmament, he now perceived the harmonious connection between the refinements of science and the wants of every-day life; and he hoped that the labour he chose to bestow upon astronomy might, while gratifying himself, be of some practical use in the end. I had the honour of being therefore again consulted upon the subject, and readily yielded my aid on the occasion.


From the sloping nature of the ground on which Hartwell House stands, and the mass of trees in the south and west quarters, the site was not very promising for an observatory of general capacity. After much examination, I

« ÎnapoiContinuă »