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the most careful and searching scrutiny into the errors of hisworkinanship; or, witli the most refined application, both ofexperience and theory, into the amount and lavvs of its flexure,whether of the telescope or b'rnb, by its own weight in differentpositions. In fact, no astronomer has ever gonc deeper into thetheory of instrumenta, or exemplified that theory by inore elaborateexperimental inquiries. The finishing band was put to a mostremarkable memoir on the effects of flexure, but a very shorttime previous to his death, which has only just seen the light (seeAstronomische Nachrichten, No. 577, et seq.), its publicntionhaving been directed in his will.

The improvement of Carlini's tables of the sun was theobjeet and result of the first five years' observations with Gary'scircle and Dollond's transit ; though other objeets of interestwere not neglected, espeeially that of an exaet determinationof the places of those stars in which large proper motionshad been remarked. But when, in the year 1820, the circleof Cary was replaccd by the larger and more aecurate meridiancircle of Reichenbach, a wider field of inquiry was opened out,and a task undertaken and conipletcd of which astronomy isonly now beginning to reap the fruits. Tliis was no less than adetermination of the places of all the stars, down to the ninth mag-nitude, in a zone of the heavens extending from 15 ° south to 45 0north declination. Previous to entering upon this great work,however, the new instrument was subjeeled to a more severe andrigid "scrutiny into the divisions of its circle, and the aecurateadaptation of its parts (by the aid of a microscopicai apparatuscontrived and executed by Pistor), than that which its predecessorhad undergone. It sustained the qideal to admiration. The zoneobservations were conimenced on the igth of August, 1821, andcompleted on the zist of January, 1833, in 536 zones, compre-heiKling upwards of 75,000 observations. The arrangement of thework, as printed in the Königsberg observations, is in the highestdegree convenient for reference. Every zone is aecompanied by asmall table, by means of which the reduetion of any one of theobserved objeets to a fixed epoch may be performed at once, and inthe shortest possible time ; so that the observations themselves, bythe aid of an index to the zones, have nearly all the advantage ofa catalogue, and that of a very high degree of precision. Theiractual reduetion and arrangement as a catalogue was conimencedin 1830 by Professor Weisse; but the promised work has not, webelieve, yet appeared. Bessel was assisted in the Observation ofthese zones by M. Argelander, who, since his removal to the di-rection of the observatory at Bonn, has continued them from the45th to the 8oth degree of north declination, the observations beingvery recently pubüshed in the first volumc of the transactions oftheBonn Observatory, in 204. zones. It will be n matter of no smallinterest, when the elements of the new planet! which have so re-cently been added to our list shall have become sufficiently knownto admit of a retrospective ephemeris being calculated, to searchthe Königsberg zones for missing stars lying in their paths, and