476 Proceedings of the Royal Society 
levels of all tlie important points in the city were determined by 
instrumental measurement, and fixed definitely by connection with 
the line of levels which Colonel Wilson carried across from the 
Mediterranean to the Dead Sea. 
This great work forms the basis on which all subsequent explora- 
tion rests, and supersedes all previous maps, such as those of 
Kobinson, Vandevelde, Symonds, Catherwood, Barclay, &c., which, 
though invaluable at the time when they were constructed, are but 
imperfect attempts in comparison with the complete plan which is 
now available for students. 
Colonel Wilson was not charged with any extensive commission 
for the purpose of excavations, and the few which he undertook did 
not lead to any important results. He was, however, the first 
explorer who gave a careful and minute account of the masonry of 
the great walls which surround the Haram or “ Sanctuary,” which is 
recognised as the site of the Jewish Temple enclosure. 
The famous excavations conducted by Captain (now Lieutenant- 
Colonel) Warren, E.E., for the Palestine Exploration Fund, were 
commenced in 1867, and carried on until 1870. They resulted in 
discoveries of crucial importance, especially with regard to the 
extent and antiquity of the Haram rampart walls, and respecting the 
ancient contour of the site of the city and of the Temple. 
The 1872 excavations were carried on at the expense of the 
German Government, in the very heart of the town, on the site of 
the old hospital of the Knights of St John. They also yielded 
very important results in the discovery of a great valley 100 feet 
deep, the existence of which had previously been denied by Canon 
Williams and other writers. 
During the years 1872, 1873, 1874, and 1875, I spent several 
months of each year in Jerusalem, and was able to supplement the 
explorations in one or two particulars. I also collected, personally 
and by aid of residents, a large number of new observations as to the 
depth of the debris, which, when added to the measurements of 
Colonels Wilson and Warren, are sufficient to justify the tracing of 
contours over the entire site of the city, showing the ancient surface 
now hidden by rubbish, and thus defining the great natural features 
described by Josephus, which are almost obliterated by the gradual 
filling in of the original valleys. 
