Considerations on tho Problem of Latitude Variation. 1 Q 



No. 1. The hanging level of the transit instrument, 



Bamberg No. 7958. 

 Nos. 2, 3. The latitude levels of the above. 

 No. 4. The hanging level of the transit instrument, 



Bamberg No. 7959. 

 Nos. 5, 6. The latitude levels of the above. 

 No. 7. The hanging level of the transit instrument, 



Bamberg No. 11508. 

 Nos. 8, 9. The latitude levels of the above. 



First the level was fitted to the trier in such a way that the 

 bubble moved in increasing sense of division in accordance with 

 the increase of the micrometer reading of the trier. Then the 

 micrometer was turned in increasing sense and set, say, to a read- 

 ing a. The l)ubble would move increasingly and come to rest at 

 /9-^„ where Q, is the resistance. Next, the micrometer was further 

 turned slowly up to, say, division « + 10. Hereupon it is turned 

 back to «-1; then again it is set at the reading «, theoretically 

 bringing the level Ijack to the original position. To this operation 

 the bubble conforms with considerable lag of time, owing to its 

 inertness, and would come to rest in decreasing sense at the point 

 /9+(?.. Let the reading of the bubble centre for the first position 

 be /S'i and for the second position be ^-i, then we have 



This process was applied to two such points alternately ; for the 

 first point, the motion was in tlie order increasing-decreasing, for 

 the second point in tlie order decreasing-increasing. This will 

 eliminate the effect of the gradual change of the pier, not to speak 

 of determining the value of one division of the level. The result 

 of my experiments is given in the following table V, in which 

 the resistance d, is expressed in terms of the unit of division of the 

 levels. 



