This work was designed for general utility, but applied more particularly to the instruments existing at Cambridge. It is pervaded by the effort towards accuracy which distinguished Challis as a practical astronomer.
The chief scope of his twenty-five years' labours at the Cambridge observatory lay in determinations of the places of sun, moon, and planets, with the immediate object of increasing tabular accuracy, and the more remote one of testing the absolute and undisturbed prevalence of the Newtonian law. He followed the methods of his predecessor, but devised valuable improvements. The collimating eye-piece, amended from Bohnenberger's design at his request by William Simms, was introduced by him in 1850, and quickly adopted at Greenwich and elsewhere (Lectures, p. 69). He invented in 1849 the ‘Transit-Reducer,’ distinguished with a bronze medal at the exhibition of 1851 (ib. p. 387; Monthly Notices, x. 182). Also, in 1848, the ‘Meteoroscope,’ a kind of altitude-and-azimuth instrument in the form of a theodolite, designed for ascertaining the varying dimensions and positions of the zodiacal light, for measuring auroral arches, and determining rapidly the points of appearance and disappearance of shooting-stars (Report Brit. Assoc. 1848, pt. ii. p. 13).
Challis published, 1832–64, twelve volumes (ix–xx.) of ‘Astronomical Observations made at the Observatory of Cambridge,’ each with an elaborate introduction, the first two containing descriptions of instruments and methods. He first in this country noticed the division of Biela's comet on 15 Jan. 1846, re-observed both nuclei in 1852, and attentively studied the physical appearances presented by Donati's comet from 27 Sept. to 16 Oct. 1858 (Monthly Notices, xix. 16). He was admitted a member of the Royal Astronomical Society on 8 April 1836, of the Royal Society on 9 June 1848, and was appointed one of a committee of three to superintend the publication of the British Association Star-Catalogue after Baily's death in 1844. Besides the works already mentioned he wrote:
- ‘Creation in Plan and in Progress, being an Essay on the First Chapter of Genesis,’ Cambridge, 1861, originally designed as an answer to Goodwin's ‘Mosaic Cosmogony’ in ‘Essays and Reviews.’
- ‘A Translation of the Epistle of the Apostle Paul to the Romans, with an Introduction and Critical Notes,’ Cambridge, 1871.
- ‘An Essay on the Mathematical Principles of Physics, with reference to the Study of Physical Science by Candidates for Mathematical Honours in the University of Cambridge,’ Cambridge, 1873.
- ‘Remarks on the Cambridge Mathematical Studies, and their relation to Modern Physical Science,’ Cambridge, 1875.
- ‘The Relation of the Scriptural Account of the Deluge to Physical Science,’ London, 1876.
- ‘An Essay on the Scriptural Doctrine of Immortality,’ London, 1880.
- ‘The Counting and Interpretation of the Apocalyptic Number of the Beast,’ London, 1881.
He drew up an elaborate ‘Report on the Present State of the Analytical Theory of Hydrostatics and Hydrodynamics’ for the British Association in 1833 (Report, p. 131), and one ‘On the Theory of Capillary Attraction’ in the following year (ib. 1834, p. 253). His contributions to scientific publications on various points connected with mathematics, physics, and astronomy numbered 225. He had thoughts of collecting into a volume a long and unbroken series of papers of a somewhat remarkable character, prepared by him as examiner for the Smith's prizes, 1836–78, but desisted, and they remain scattered through the university calendars for those years.
[Monthly Notices R. A. Soc. xliii. 160; Royal Soc.'s Cat. Sc. Papers, vols. i. and vii.; Nature, xxvii. 132; Engineer, liv. 474; Challis's various works.]
CHALLONER, RICHARD, D.D. (1691–1781), catholic prelate, son of Richard Challoner, a wine cooper at Lewes in Sussex, and his wife, Grace Willard, was born on 29 Sept. 1691, and baptised by a minister of the dissenting sect to which his father belonged. Soon afterwards the father died, leaving his young widow with her infant child totally unprovided for. Fortunately she found a refuge for herself and her son first in the family of Sir John Gage of Firle in Sussex—a family distinguished by its fidelity to the ancient form of religion—and afterwards in that of Mr. R. Holman, who resided for some time at Longwood, near Winchester, and subsequently at his own seat of Warkworth in Northamptonshire. In both these families Challoner was instructed in the tenets of the catholic church, of which his mother was at that time a member. It appears, however, that he remained a protestant until he was about thirteen years of age. At Warkworth he had the celebrated controversial writer John Goter for his tutor. In 1704 he was sent to the English college at Douay, and he took the college oath in 1708. The annals of that seminary relate that ‘in all his exercises, whether private or public, he showed an excellent genius, quick parts, and solid judgment.’ So diligently did he apply himself to his studies that although twelve years was the time usually allotted, he went
