J, H. Lane on an Automatic Comparison of Time. 48 
e ' itu . erve : 
Year, [From solar spot AYE irom a. | amplitude. | Difference. 
1840 B18 9:10 9-08 —002 
1841 295 8-23 806 0-17 
1842 19°2 1-83 7°83 0 
1843 TAL 7-46 +005 
1844 122 7-55 "51 0-04 
1845 32:4 | 8-34 8:53 -LO-19 
maximum in 1848, By computation from the solar spot observy- 
ations, the amplitude at that time would amount to 11’-00, the 
whole range of the inequality of the diurnal variation would 
therefore be 11/-00—7'-46=3'54. 
_ Itis much to be desired that this interesting branch of phys- 
ical enquiry be further studied, as it forms one of the links con- 
necting terrestrial with cosmical phenomena. 
Art. V.—A Visual Method of effecting a Precise Automatic Com- 
parison of Time between distant stations ; by JONATHAN HOMER 
Lang. (With a plate.) 
those situations, also, where submarine or subterranean lines take 
First, an intense light shown at one station, A, and viewed at 
the other station, B, as a star. 
