382 Proceedings of the Royal Society 
miles, and although a large proportion of these are of little 
value, the result of this systematic examination of the nomenclature 
has been the recovery of about 150 ancient sites, which are newly 
identified with places mentioned in the Bible, while a yet larger 
number of names connected with the Byzantine and Crusading 
history of Palestine have also been recovered. 
The elevations of the trigonometrical stations above the sea were 
obtained by vertical angles with the theodolite, and checked by 
means of measured heights along the coast. The error in these 
heights does not appear to exceed three or four feet on an average; 
Other elevations were observed with aneroid barometers, and 
checked by readings taken at bench marks or at trigonometrical 
stations and by readings of the mercurial barometer in camp. A 
line of levels had been run from Jaffa to the Dead Sea in 1864 by 
Captain Wilson, RE., and with this our trigonometrical observations 
agreed very well. The summer level of the Dead Sea was thus fixed 
at 12 92 ’5 feet below the Mediterranean, the surface in summer 
being about fifteen feet lower than in winter. 
In 1875 a second line was run by the survey party from the Bay of 
Acre to the Sea of Galilee, a distance of about thirty miles, and the 
level of this lake was thus fixed at 682 ’5 feet below the Mediter- 
ranean. This piece of work was carried out under a special grant 
from the British Association, former estimates of the depression 
having ranged from 300 to 600 feet. 
By means of these levels and of observations to trigonometrical 
stations between the two lakes and farther north, the fall of the 
Jordan was determined throughout the whole of its course. 
The rate at which the survey was carried on increased gradually 
as the party became more accustomed to the country and better 
acquainted with the language and customs of the natives. At first it 
did not exceed fifty square miles in a month, but after leaving Rablus 
an average of 100 was obtained. In 1873 this was increased to 150, 
and in 1874 to upwards of 200. The party was strengthened in the 
latter year, when an average of 270 square miles per month was 
attained, and kept up almost to the end of the survey. The most 
rapid piece of work was the survey of the Desert of Judah. The 
triangulation being very large and the detail less close than in the 
cultivated districts, the survey of this desert was completed in ten 
