Survey of Jerusalem 1 69 



transparent to rays emitted from solid incandescent bodies, 

 a combination of the two makes it possible to separate, 

 almost entirely, the purely thermal and simply luminous 

 rays in any spectrum. 



Nov. 24th, i6oth meeting. Sir H. James reported that 

 Captain Vincent, with a party of sappers, had completed 

 a survey of Jerusalem, for which purpose they had been 

 permitted to establish a station within the Haram area, 

 every facility having been given by the Turkish authorities. 

 Captain Vincent, by descending a well, had found a conduit 

 with Roman work, 82 feet beneath the surface, from which 

 three steps led down to running water. 1 Dr. Falconer 

 called attention to the discrepancies of statements about 

 the relative levels of the Mediterranean and the Dead Sea, 

 and the depth of the latter, and hoped that the above-named 

 party would be directed to settle these points. 2 



Sir H. James referred to some anomalies in pendulum 

 observations at Portsoy, and stated that, according to 

 Mr. Otto Struve, the same had been noticed over a tract 

 of country running east and west of Moscow. 



Dec. 22nd, i6ist meeting. Mr. Busk announced the 

 discovery by Captain Brome of a second cave in Windmill 

 Hill, Gibraltar, in which abundant human remains and 

 stone implements had been found embedded in, or covered 

 by, thick layers of stalagmite, but the excavation had not 

 yet been carried deep enough to disclose any mammalia, 

 except man. 



1 This survey stimulated interest in the antiquities and topography of 

 Jerusalem and Palestine. The Palestine Exploration Society was founded 

 in 1865. Excavations at Jerusalem were begun in 1866 by Captain (after- 

 wards Sir Charles) Wilson and Lieutenant Anderson, with important 

 results. Between 1867 and 1870 Lieutenant Warren (afterwards Sir 

 Charles), with some non-commissioned officers of the Royal Engineers, 

 carried out works which settled many disputed questions in regard to 

 the ancient Temple area and underground Jerusalem. 



2 These discrepancies were mainly due to the fact that in all but two 

 cases the level of the Dead Sea had been determined by barometrical 

 observations. Triangulation by Lieutenant Symonds gave 1312 feet 

 below the Mediterranean ; another one by Lynch gave 1317 feet. The 

 result afterwards obtained by the Ordnance Surveyors was 1292 feet 

 (the level varies some 5 feet with the season). 



