don demolished a house in Chelsea Hospital with a 300-kgm. bomb.
The raid of March 7 1918 was remarkable as being the only occasion on which aeroplanes attacked London in the absence of any moonlight. The navigators of the attacking Giants were helped by a bright aurora. This made the night unusually light, and gave a constant bearing of fair accuracy to the pole. Warrington Crescent was badly hit, most of the houses being wrecked.
To turn to the airships, the disaster of Oct. 19-20 1917 was followed by the destruction of four more ships by explosion in their sheds, and raiding was not resumed until the nights of March 12 and 13 1918. Both these raids were made at an immense height, and although Hull and West Hartlepool were bombed, the damage did not amount to much. The casualties comprised nine killed on the two nights.
Five airships of the newest and largest type, under Capt. Strasser, attacked the Midlands on the night of April 12. Although more than seven tons of bombs were dropped in the neighbourhood of big towns, the result was very small, and only five people were killed.
The end of the airship raiding came on Aug. 5-6 1918. Five ships came up to the coast of Norfolk, no bombs were dropped on land, but 1^70, the latest word in airship construction, was destroyed, with Capt. Strasser on board, by Major Cadbury, flying a DH4 machine.
In the great aeroplane raid of May 19 1918 the Germans made their maximum effort in this form of attack; between 30 and 40 Gothas of the 3rd Bombing Squadron took part, with at least two Giant machines. Thirteen of the raiders managed to get over London. The casualties included 49 killed, and 130,000 worth of damage was done in the London area alone. But the defence had by now made very real progress.
Eighty-four aeroplanes, nearly all of excellent performance, went up in pursuit, and all landed safely. The anti-aircraft guns fired upwards of 30,000 rounds. The plans worked well in that the defending pilots were assisted instead of being hampered by the gunfire and searchlights. The Germans lost seven machines three shot down in air combat, three destroyed by gunfire, and one from engine failure.
This success of the defence was final, and London was saved from further bombing. The Germans turned their attention to Paris, which now sustained a long series of raids.
A new system of defence control was in course of being installed in London at this time, but it did not come into full operation until Aug., and it was therefore never tested in an actual raid. It provided a method by which the defence commander could follow the course of raiding machines, and could instantly transmit information and orders to the pilots in the air by wireless telephone. It was calculated that this system would increase the power of the defence at least fourfold.
A proof of the efficiency of defence by aeroplanes, assisted by a good organization on the ground, was furnished by a squadron, manned by pilots trained in the London methods, that was sent to France in June 1918 to cope with night bombing near the line. In a very short time they accounted for 26 German machines, and they practically stopped bombing in their area, with no loss to themselves.
Conclusion. We have now traced the way in which raiding and defence grew up together, and the eventual success of adequately equipped and organized defences. In addition to casualties 1,413 killed, 3,407 injured in all and damage, the German raids on England produced actual results by no means negligible. A night raid stopped munition work over a large area. In order to establish a defence, men and material were kept back from France. This was particularly felt in the case of aeroplanes and pilots. Two hundred aeroplanes of the best performance and 200 highly trained pilots were available about London at a time when they would have been of the utmost value on the western front. The moral effect of raiding is found to depend not so much on actual damage as on the success or ill-success of defensive measures. In London, the barrage, the "aprons," and the aeroplane defence did much to allay fears that had arisen when there was apparently no answer to the attacks. (E. B. A.)
AIRSHIP: see Aeronautics.
AITKEN, JOHN (1839-1919), British physicist, was born at Falkirk Sept. 18 1839. He was educated at Falkirk grammar school and Glasgow University, and trained as marine engineer at R. Napier & Sons, Glasgow. He lived at Falkirk, where he carried out his great experiments on atmospheric dust in relation to the formation of clouds and mists (1882), on the formation of dew (1885, see 8.136) and on the laws of cyclones (1891). His instrument for counting the dust particles in the air (see 8.714, 18.279) has been utilized in principle by many later workers. He also invented new forms of thermometer screens and powerfully aided the development of meteorology. He was elected F.R.S. in 1889 and was awarded the Royal medal in 1917. He also received the Keith medal (1886) and Gunning prize (1897) from the Royal Society of Edinburgh, in whose Transactions and Proceedings most of his valuable contributions were published. He died at Falkirk Nov. 14 1919.
AKHWAN MOVEMENT, a religious revival or reform, confined mostly to the Nejd districts of Arabia. The term akhwan, or ikhwan, signifies "brethren," and the tenets of the brotherhood are those of Wahabism revived and intensified (see 28.245). The movement, recognized by Ibn Sa'ud, Emir of Nejd, had taken definite shape after 1910; and in 1921 it still seemed likely to have far-reaching effects upon the attitude of the people of Central Arabia towards other Arabian communities and even to the outer world.
ALABAMA (see 1.459). In 1920 the pop. was 2,348,174 as against 2,138,093, in 1910, an increase of 210,081, or 9-8 %, as compared with 309,396, or 16-3%, in the preceding decade. Although the proportion of urban pop. was greater than in 1910, yet in spite of the marked development of mining and manufacturing interests, more than three-fourths of the inhabitants were still rural and chiefly agricultural. The urban pop. (inhabitants of cities of 2,500 or more) was 509,317; the rural, 1,838,857.* The growth of pop. in the chief cities is shown in the following table:
1910 per cent.
Birmingham 178,270 132,685 34-4 Mobile . 60,151 51.521 16-8 Montgomery 43464 38,136 14-0 Bessemer 18,674 10,864 71-9 Anniston 17.734 I2 >794 3^-6 Selma , 15,607 13,649 14-2
The distribution of pop. by race was as follows: whites, 1,447,032; negroes, 900,652; Indians, 405; Chinese, 59; Japanese, 18; all others, 8. During the decade 1910-20 the white pop. increased 17-8%, while the negro pop. decreased 0-8%, due to male negro migration to northern industrial centres.
Agriculture. There were 256,099 farms in 1920; 262,901 in 1910, a decrease due to the negro migration noted above, but there was a marked increase in total production. The state Department of Agriculture estimated that in 1920 there were harvested 5,630,000 tons of commodities compared with 5,203,000 tons for the year 1919. The same department made the following estimates of the acreage, production and value of crops in 1920: Crops Acres Production Value Corn ,277,000 ,234,000 bus. $67,057,000 ,868,000 ,000 bales ,515,000 Cottonseed . ,700 tons ,839,000 Peanuts ,700 ,024,000 bus. ,936,000 Hay ,440,000 ,324,000 tons ,123,000 Velvet beans .700 ,100 tons ,914,000 Cowpeas ,200 ,113,000 bus. ,622,000 Irish potatoes ,900 ,215,000 bus. ,250,000 Sweet potatoes ,800 ,585,000 bus. ,939,000 Sorghum syrup ,900 ,917,000 gal. ,340,000 Sugar-cane syrup ,700 ,298,000 gal. ,643,000 Oats ,000 ,833,000 bus. ,740,000 Wheat . ,000 ,000 bus. ,594,000 Soy beans ,000 ,000 bus. ,000 Tobacco . ,000 ,100,000 Ib. ,000 Total harvested ,117,900 $2^5,520,000