GAUSS AND WEBER ON TERRESTRIAL MAGNETISM. 89 



In Munich, besides Prof. Steinheil, MM. Hierl, Lamont, Lip- 

 polt, Meggenhofen, Mielach, Pauli, Pohrt, Recht, Schleicher, 

 Schroder, Siber, and Zuccarini. 



Other observations of some of these six terms have also come 

 to oui' hands, but too late for insertion in the plates ; this is the 

 more to be regretted, as, for the most part, they accord with the 

 others in a veiy interesting manner. The results of the obser- 

 vations made at Upsala, in the September term, 1836, which are 

 of this kind, are printed in the sequel. The Milan observations 

 of November, 1835, Avhich were also received after the curves for 

 the six other stations had been drawn on stone, were inserted 

 below them ; but for this circumstance, their place would have 

 been between the Munich and Palermo obsei'vations. The Got- 

 tingen obsei'vations have required no process of reduction, being 

 drawn in accordance with the divisions of the scale as indicated 

 in the margin, the height of each square being taken as two divi- 

 sions of the scale in all the terms, with the single exception of that 

 of January, 1836. The changes during that term are the greatest 

 which have been hitherto observed, and rendered it necessary, in 

 order not to increase the height of the page too much, to allow 

 three divisions of the scale for each square. Increasing numbers 

 always denote an advance of the needle from right to left, — in 

 other words, diminishing westerly variations. The observa- 

 tions at Breslau, Freiberg, the Hague, and Leipzig, where the 

 di\dsions of the scale are nearly of the same magnitude as in 

 Gottingen, have been di-awn according to the same proportion. 

 The distance between the curves is an arbitrary quantitj'^ in each 

 case, determined solely by its fulfilling the one object of keeping 

 them at a convenient distance apart. 



For those stations where the value of the divisions of the scale 

 differs considerably fi'om that at Gottingen, the original numeri- 

 cal results were multiplied in each case by a common factor, ex- 

 pressing, as nearly as possible, in convenient numbers, the pro- 

 portion to the Gottingen scale. Thus, the various curves in each 

 term are represented veiy nearly according to a common scale. 

 In the Januaiy term alone the scale of representation is somewhat 

 more unequal, the cause of which does not merit any mention in 

 this place, as it suffices to know the scale for each curve. In 

 the three first terms the height of each square corresponds to 

 tiie following values of arc, viz. : 



