DISCOVERY 



171 



before that which has hitherto been generally accepted. 

 The relation of the different types of palaeolithic 

 implements to the glacial epochs has also been the 

 subject of a number of articles, wTitten from different 

 points of view, which have appeared and are still 

 appearing in Man, the monthly journal of the Royal 

 Anthropological Institute. As a result it would appear 

 that the opposing schools of thought are gradually 

 narrowing down their differences to a point at which 

 the issue may be submitted to the practical test of 

 further geological investigation. The subject is to 

 be ventilated further in a joint discussion between 

 the Anthropological and Geological Sections of the 

 British Association when that body meets at Hull in 

 September next. 



The Anthropological Section will also discuss at the 

 same meeting various matters relating to anthropologv 

 and archfeolog\ of the north-east coastal area of 

 England. Among these will be the important question 

 of the occurrence in this country of the early Neolithic 

 culture known as Magelmose, the character and dis- 

 tribution of earlv Scandinavian art in the north of 

 England, which will form the subject of a communi- 

 cation from that well-known authoritv. Mr. W. <'i. 

 Collingwood, and Professor Allan Mawer, of Li\'erpool, 

 will deal with the ethnological evidence afforded by 

 the study of the place-namss of this area. 



;je 4: 4: ^ He 



The Rutenberg controversy will have taken many an 

 ex-warrior's memory back to Palestine, and in par- 

 ticular to the valley of the Jordan, whose waters are 

 apparently to be utilised for irrigation and for the 

 generation of electricity. Little over four years ago, 

 when two successive raids were made by British troops 

 across the river and into the hills of Moab, the valley 

 was the scene of some of the intensest fighting in any 

 " side-show " during the war. As is well known, the 

 valley just north of the Dead Sea is 1,200 feet below 

 ocean level, and is the lowest place on the earth's 

 surface. The second raid was carried out in steaming 

 heat, with the thermometer often at 115° in the shade, 

 and amidst swarms of flies, lice, and mosquitoes. It 

 ■w'£is only a partial success ; the Turks had brought up 

 strong reinforcements. The whole valley, of course, 

 came into our possession in the final offensive in the 

 early autumn of the same year. The Jericho side of the 

 river is dry and barren, but the Plain of Moab, which is 

 already roughly irrigated, is a most fertile producer of 

 grain. There is no doubt that the river, whose current 

 through much of the year is turbulent, could be 

 successfully harnessed for the production of electricity. 

 Many of the Jiora and fauna of this weird region are 

 unique. A " large scale " expedition of zoologists 

 and botanists to the valley would obtain most important 

 results. 



The Progress of Aerial 

 Photography 



By Major W. T. Blake 



Aeri.\l photography first came into prominence 

 during the war, when its value at once became 

 apparent. For some little time considerable difficulty 

 was experienced in obtaining a suitable camera, and 

 still more in the production of a long focal lens of 

 large aperture. 



Generally speaking, once aerial photography had 

 been developed, it was found that the camera would 

 record many objects which were frequently not 

 observed by the pilot or observer. Photographs were 

 usuallv taken with the camera pnintincr vertically 



Fig. I. vi'RiiS pRtoi Tin; aik (Fubkuaky 1,1; sii.imi .'. 1 



C.\THEDR.\I, AND CI.OTH HALL IN THE CENTRE OE THE 

 PICTURE. 



A unique photuqrciph, never before published. 



downwards either through an aperture in the floor 

 of the aeroplane or strapped to the side of the fuselage. 

 It was usual for the pilot to fly on a level keel at an 

 altitude decided previously, whilst the observer took 

 the photographs as desired. It was generally found 

 best to fly up-wind whilst making the exposure in 

 order that the ground speed of the aeroplane might 

 be as little as possible, though it was found that when 

 taking photographs at a great altitude an extremely 

 fast exposure was not necessary. 



Photographs were taken either singly of specific 

 objects, or in the form of an overlapping series covering 

 a long line of country. These photographs were then 

 printed and joined up in one continuous strip, showing, 

 for example, a sector of the enemy's trenches. When 

 it was desired to photograph any given area, one or 

 more machines flew over this area on certain pre- 

 determined lines, each taking a series of strip photo- 

 graphs. These were afterwards fitted together in a 



