4 ANNIVERSARY ADDRESS, 
so far as it went, and then transporting chronometers the rest of the 
way, and no determination of personal equation was thought neces- 
sary. The second value was obtained since the telegraph line was 
completed, by good observers, good instruments, and every precaution, 
including a careful determination of personal equation. It was at 
first proposed to take a mean of these values, but ultimately the 
later value was taken. I merely mention this to show what the 
difficulties are like, and that there is some uncertainty even in 
telegraphic determinations of longitude. As the report on the 
determination has been agreed to ready for publication, I will not 
detain you about it now, except to say that the resulting longitude 
of Sydney is 10h. 4m. 49°55s., which is 1:26s. less than the value 
derived from my observations of the moon, which were affected 
by uncertainty in the moon’s place and the possible personal 
equation in observing the moon between the observers at Green- 
wich and Sydney. Any error of this sort would be magnified about 
twenty-five times in the resulting longitude, and therefore the above 
difference would represent a difference caused in this way of 005s. 
There is a very general impression, borne out by the evidence 
which geology has furnished, that at least the east coast, if not all 
Australia, is rising in relation to the mean level of the sea. The 
late Rey. W. B. Clarke, in a report to the Port Jackson Harbour 
Commission, said “that the coast has risen in former geological 
epochs, and that it has risen during the present epoch is capable 
of distinct proof.” ‘Raised beaches of shells, which are not 
kitchen middens, may be seen about 25 feet above the sea, near 
Ryde on the Parramatta estuary, and at Mossman’s Bay, in Port 
Jackson, at a height of 132 feet above high-water.” Again— 
“ Regarding the whole coast from Broken Bay to Botany Bay as 
mere peninsulated fragments, united only by low isthmuses, bare 
or covered with sand, as they actually are, one may still see that 
there must have been oscillations of level, and finally elevation.” 
Speaking of other portions of the coast, Mr. Clarke says :—* At 
Adelaide, in 1855, the railway between the city and the port was 
a and Mr. austere eon that in four 
