68 PROPOSED CORRECTION TO THE ASSUMED 
In the meantime, I must express it as my opinion that the 
longitude of the Sydney Observatory, as given by Messrs. Scott 
and Stone, really requires a considerable positive correction. 
Before many years elapse, telegraphic communication will pro- 
bably be so well established that we shall by that means be 
enabled to accomplish the accurate solution of the problem, just 
as in the case of Washington, whose longitude from Greenwich 
has been determined satisfactorily in this way within a second of 
im 
the paper to the Council in time for their meeting on the 29th 
instant, in order to its approval for the General Meeting on the 
5th proximo. 
Windsor, May 25th, 1878. 
The following supplementary paper, on the same subject, was 
forwarded by Mr. Tebbutt, and read at the meeting of the 
Astronomical Section of the Society, held on June 13th :— 
On the 5th instant I read before the general monthly meeting of 
the Royal Society a paper on a correction to the assumed longi- 
tude of the Sydney Observatory, deduced from observations of 
lunar occultations of stars, made at my observatory, Windsor, in 
the years 1866-68-69-70-73-74. In that paper twelve occultations 
of well-determined stars were discussed, two of which were 
unfavourable for longitude results. One of these in particular 
was rejected, as having occurred near the moon’s northern limb, 
and the resulting longitude of my observatory was made to 
pe on the eleven remaining occultations. This value 13 
10h. 8m. 23°34s. E. of Greenwich; and to it was added 1m. 30°04s., 
the difference of longitude between the Sydney Observatory and: 
mine, as determined from telegraphic signals in May, 1869, 
giving 10h. 4m. 53°38s. E. as the concluded longitude of the 
rmer from Greenwich. Having reason to suspect that the 
telegraphic difference of longitude just stated was considerably 
too great, I requested the co-operation of Mr. Kussell in a new 
