Phfiijffbr of Matheiil'dtks at GotiiTtge'n^ §9 



from thefc and other books ;' Bat he had no money to piir- 

 thafe inftruments and telcfcopes. He therefore did what has 

 been fince pra6lifed by Hcrfch'^1': hfe'cpnftrufted fome him*, 

 felf, according to the dlredions' given by Hertel and Leut- 

 hiann. Baumann's lifter, \yhom Kaftner afterwards mar- 

 Iried, recommended herfelf to hl^ notice by her attachment 

 to thcfe purfuits. 



Having obtaiiied from Baumann a tclefcope the obje^lH:- 

 glafsof \Vhifch had a focus of fix feet, and which magnified 

 33 times, he employed it for obferving the cOmet of 1744, 

 much better than the one he had borrowed in 174a* He 

 haid'ii'o tinle-keeper, but he purchafed at a fale a brafs qua- 

 drant of half a Rhinland foot radius, with fixed fights, and 

 divided into qu.irters of a degree. ■ . . 



In thfe courfe of time he caufed m()i'e aiili' larger telefcoped 

 to be conftrufted, which he employed as far as could be pof- 

 fibly done where hfe had no mearis to determine accurately 

 the time. With a 26 feet telefcopc of this kind, he faw iit 

 the furi, as he affures us himfelf, white lumhioiis fpots^ fuch 

 as Mr. Schroter of Lilienthal obferved afterv^^ards With the 

 beft telcfcopes. With the f:inie tekfcope Baumann obfervfed, 

 a dark red ring round Mercury during his tranfit over the 

 fun btt the 6th of May 1753. On the 9th of O^iober 1751, 

 Kaftner obferved an occultation of Jupiter; and on the nth 

 of February, niext year, one of Venus by the mnon : of both 

 thcfe phaenomena, arid the circumftances attending them, he 

 publifhed an account in the eighth volume of the Hamburoh 

 Magazine. It may there be fcen that at this period he em* 

 ployed himfelf in obfervirtg the heavens as much as his fitua- 

 lion would admit. 



In the year 1737 he had bc^gtm to learn algebra with 

 Heinfius. Next year, Heinfius, having finiflied his courfe, 

 made a tour to Peterfburgh^ and on his return in 1745 

 Kaftner requefted leave to be prefent at the obfervatory while 

 lie made his obfervations; but he could not get his wifhes 

 gratified. In this point Heinfius was exceedingly referved, 

 and it was only with great difficulty that baron Kregel could 

 obtain a fimllar favour. In other rcfpe6ts Kaftner kept up 

 a ver\^ frJendly intercourfe with Heinfius. 



N 2 hx 



