88 View of the Progress of 



time : so that we may depend on the difference of longitude, as 

 being probably correct within less than half a second of time. 



XXI. Lindenaiis further Account of Pons s Comet of \^\1. 

 Remarks some unexpected anomalies in its illumination. 



XXII. Wurm on Computations with small Arcs. 

 Tables for readily finding the logarithms with accuracy. 



XXIII. Wurm's Continuation of Investigations respecting ancient 



Eclipses. 

 Chiefly those mentioned by Zach. Observes that some omis- 

 sions in a celebrated almanac may have been occasioned by a 

 reliance on Pingre's catalogue in the Art de verifier les dates: [nor 

 are they the only omissions in that catalogue.] 



XXIV. Gauss on some Corrections to be applied to Bordas 



. Repeating Circles. 

 Chiefly for the purpose of making the visual line parallel to the 

 plane of the circle. The author employs an image reflected from 

 quicksilver, for bringing the instrument into a vertical plane. 



XXV. Zach on Trigonometrical Operations in Tuscany. 

 From some very numerous series of observations, of his own 

 and Inghirami's, the author forms the important conclusion, that 

 an error of from 5 to 10 seconds may remain undetected in the 

 mean of many hundred observations with the 12 inch repeatino- 

 circles of Reichenbach. The paper contains a catalogue of the 

 latitudes and longitudes of places in the neighbourhood of 

 Florence. 



XXVI. Olbers on the Influence of the Moon upon the Weather. 



This distinguished mathematician and most respectable phy- 

 sician, the father of a little colony of science and refinement, in a 

 town occupied before his time almost exclusively by the plodding 

 pursuits of commercial speculations, undertook, some time since, 

 in a public lecture which he delivered to a mixed audience, tlic 



