Astronomy in Germany, Jo r 1818. 85 



ployment of fractions of seconds must, in this case, also be 

 commonly superfluous. 



The author observes that in a former essay he had found the 

 most probable error of Carlini's circle, or of the three foot mul- 

 tiplying circles of Milan and Ofen, equal to ",75, which is only 

 -J-^ of that of the determination of the right ascension by a 

 transit : and even the more imperfect circle of Konigsberg, with- 

 out being turned round, affords a precision about one-third 

 greater than that of the right ascensions. 



III. Bessel on the Influence of the Changes in the EartKs Sub- 

 stance upon the Latitudes of Places, 



Demonstrates that no human operations can produce a sensible 

 alteration in the conditions of the earth's rotation. 



Mr. Laplace has more lately advanced the ingenious obser- 

 vation, that any material diminution of the mean temperature of 

 the earth's substance might have been detected by the diminution 

 of the length of the day : and we shall find, on computation, that 

 a single degree of Fahrenheit might make an alteration of nearly 

 a second in the diurnal period of rotation, and four or five minutes 

 in the length of the year. 



IV. Bohnenberger on the Adjustment of Astronomical Circles. 

 By means of two objects at opposite points of the horizon, with 

 some other expedients of a similar nature. 



V. Muffling'' s History of the Measurement of the Rhine. 

 With remarks on the best modes of executing maps. 



VI. Hagen's Calculation of Observations of the Solar Eclipse of 

 November 1816. 

 Finds about 9' 22 ",46 for the diflerence of longitude of Black- 

 heath and Paris, according to Mr. Groombridge's observation of 

 this eclipse, which, however, does not agree remarkably well with 

 others. At the end of the paper we have the formulas employed 

 by Bohnenberger in the calculation of eclipses, and some very 

 convenient tables of Professor Bcssel, corrected and enlarged. 



