INTRODUCTORY AND HISTORICAL. 



submitted to the test of rigorous computation in combination with the rest, exhibited gross dis- 

 cordances. Many circumstances, of which an account will be found in Encke's second treatise, 

 combined to place Father Hell in a very unfavorable light, and several astronomers, prominent 

 among whom was Lalande, did not hesitate to accuse him of having fabricated or changed his 

 observations. Neither do his demeanor at the time, nor his published observations of the 

 eclipse on the next day, tend to diminish the suspicion ;* and the cool investigationf of the case 

 by Encke, after the lapse of considerably more than half a century, leaves his observations and 

 his character under a heavy cloud. The long delay prior to making public his results seemed 

 best explicable by his desire to obtain as many other observations as possible, in order subse- 

 quently to give the most plausible figures as his own. Unfortunately for himself, he committed 

 an error in computation,! which, like that of his counterpart, the Chevalier d'Angos, sufficed, 

 under the rigorous scrutiny of the master Encke, to secure the ultimate detection of the untruth. 



In the year 1834, ten years after the publication of Encke's second treatise, Prof. Littrow, of 

 Vienna, learned that some of the papers of Father Hell were in the possession of an Austrian * 

 gentleman, the Baron von Miinch-Bellinghausen, into whose hands they had come after the 

 death of his uncle, Baron von Penkler, who had been a zealous admirer and patron of Father 

 Hell. In the hope of obtaining some clue to the celebrated Wardoehuus observations, Prof. 

 Littrow asked permission to consult them, which was not only readily granted, but furnished 

 occasion for the presentation of all Hell's MSS. to the Vienna observatory. 



Prof. 0. L. Littrow entered with care upon the investigation, and was rewarded by the dis- 

 covery of Father Hell's astronomical note-book for the days June 2-4, 1769. Its contents, with 

 other interesting documents, were soon printed, and appeared at the close of the year. They fully 

 corroborate and justify previous suspicions. The chief figures, especially the times of entrance 

 upon the solar disc, had been for the most part erased, and with a darker colored ink. Two 

 other passages, the one relating to the observations of Sainovicz, the other to those of Borgre- 

 wing, had been so thoroughly obliterated, that Prof. Littrow was only able to conjecture the 

 three first letters of the one and the first and last letter of the other. From an investigation of 

 such figures as remained legible and unaltered, he succeeded in finding one observation of the 

 ingress by Borgrewing, and one of the egress by Hell, upon which reliance appears warran table. || 



The reasons given by Littrow, and unhesitatingly accepted by Encke, If are chiefly these. 

 Although, in reply to Lalande, Father Hell had publicly offered to exhibit the original note- 

 book, free from erasures, and giving the observations just as finally published by him, Littrow 

 found both clear and undefaced documents containing the quantities as prepared for publication, 

 and this note-book, which was as manifestly not designed for the press. It contains remarks, 

 notes, and comments, in chronological order ; the hand-writing is unequal and frequently 

 changing, observations never made public are here noted down, together with many jottings 

 and memoranda which could not have been intended for the public. The important observations 

 were chiefly obliterated, with great care and thoroughness, as were also sundry remarks con- 

 cerning them. There can be no doubt that the evidence is sufficient to establish this note-book 

 as being the identical one used at Wardoehuus, and that this establishment of identity 

 discredits the published observations and the truthfulness of Father Hell, but provides few new 

 figures upon which reliance may be placed. 



Encke submitted these new-found observations to careful scrutiny within a few months after 

 their discovery. He found that had Father Hell not altered his observations of the eclipse, 

 the times actually observed and originally recorded would harmonize, but that in his desire to 



Sec SCHEIBEL, ArdeUung mi Mathematische Bucherhmntnut ; Slwk 4. App. to the 1st preface to 2d edition, 

 f Venuidurchgang von 1769, pp. 17-20, 24-27. 

 \Abh. d. Berlin. Acad. 1835, p. 305. 

 SCHUMACIIEB, Ast. Nachr. XII, p. 71. 



|| Paler HELL'S Rate nach Wmdoe und seine Beott. de* Venwsdurclyangt in Jahre, 1769, von C. L. Lnrnow Wien ; 1835. 

 fl Abh. der Berlin. Acad., 1835, p. 303. 



