544 



NATURE 



[October 27, 1910 



sphere or from gases existing in the interior of the earth, 

 and that similar processes may even have occurred in the 

 sedimentary rocl^s. 



The third part of Terrestrial Magnetism and Atmo- 

 spheric Electricity for the present year contains two valu- 

 able tables of corrections to the British Admiralty, the 

 German Admiralty, and the United States Hydrographic 

 Department magnetic charts of the North Atlantic, by Dr. 

 L. A. Bauer and Mr. W. J. Peters, based on the observa- 

 tions made by the magnetic ship Carnegie during her 

 recent cruise. Over almost the whole area the three charts 

 show too low values for the west magnetic declination, the 

 error being generally less than a degree, but in some cases 

 it is nearly 3°. As the error is in the same direction for 

 5000 miles, it may result in a serious error in the position 

 of a vessel at the end of a voyage. The corrections to 

 the dip are not always of the same sign ; their average 

 magnitude is nearly 2°, and the actual amount in tine case 

 exceeds 4°. Over most of the region the values of the 

 horizontal intensity given in the charts are too high by 

 8 units in the third decimal, C.G.S. units. 



.'\ NEW electric generating station was opened on 

 October 12 at the Northampton Polytechnic Institute. 

 The plant was supplied by Messrs. Siemens Brothers 

 Dvnamo Works, Ltd., chiefly for instructional purposes 

 as an example of the latest ideas in central station prac- 

 tice, and comprises electrical apparatus for alternating- and 

 for continuous-current working. The buildings of the 

 polvtechnic are sufficiently large to present experimental 

 facilities on an engineering scale for most of the problems 

 which have to be handled in larger stations. It is in- 

 tended to run the station on a thoroughly commercial 

 basis ; the coal, wages, and other expenses will be strictly 

 charged up, and every unit of electrical energy supplied 

 for the purposes of the work of the polytechnic will be 

 metered regularly and sold to it. The senior students, 

 with the help of the technical staff, will take charge of 

 this work. The main features of the plant are two gas- 

 driven sets, each consisting of one continuous-current 

 generator and one high-voltage alternator In tandem. Tne 

 polytechnic authorities have issued for the use of intend- 

 ing students and others a full and well-illustrated descrip- 

 tion of the details of the whole plant, including gas- 

 engines, suction gas-producer plants, alternators, motor- 

 generator set, switchboards, transformers, and so on. 



Commenting on the Atlantic airship voyage, the 

 Engineer for October 21 does not pretend to any regret 

 that the attempt has been an unqualified failure. Nothing 

 of any value could have been expected from such a voyage 

 arranged for spectacular purposes only. Enough, and 

 more than enough, has been done to make the conquest 

 of the air spectacular. If flight in its varied forms is to 

 rise above the level of a mere sport, it is time that a little 

 steady humdrum, useful work was entered upon, and that 

 the praise of the public and the winning of prizes were 

 forgotten. Much remains to be done, and it is well that 

 it should be done steadily and scientifically by honest spade- 

 work, and not under the glamour of popular sensa- 

 tionalism. 



The successful launch of the White Star liner Olympic 

 at Belfast on October 20 gives occasion for a long illus- 

 trated article in Engineering for October 21. With a 

 total weight of 27,000 tons, it can be understood that 

 very careful provision had to be made to ensure the 

 successful floating of the ship. The standing ways were 

 about 800 feet long and the sliding ways about 700 feet 

 long. The ship overhung the cradle aft to the extent of 

 NO. 2139, VOL. 84] 



80 feet, and forward to about 50 feet. The average 

 pressure on the ways was only just above 3 tons per 

 square foot. The declivity of the ways forward was 

 f-inch per foot, and aft J-inch per foot. On the occasion 

 of the launch the weather was perfect, with a slight stern 

 wind. The pressure on the hydraulic ram of the trigger 

 arrangement was 435 tons, and on this being released 

 the ship moved at once, the hydraulic starting jacks not 

 being used. The time taken was sixty-two seconds, and 

 the maximum speed attained was 125 knots. When 

 brought to rest, the bow of the vessel was 500 feet from 

 the end of the ways. Messrs. Harland and Wolff deserve 

 most hearty congratulations on their success, this success 

 being due, in a large measure, to the minuteness and 

 precision with which every detail connected with the 

 operation had been anticipated. 



A BOOK on " English Philosophy," by Mr. Thomas JL 

 Forsyth, is shortly to be issued by Messrs. A. and C. 

 Black. Its aim is to give an outline of the development 

 of English philosophy from Bacon to the present day. 



Erratum. — The author of the revievi' of Prof. Seward's 

 " Fossil Plants " in Nature of October 20 writes : — " May 

 I point out a slip, for which I am responsible, in mv 

 review? On p. 491, column 1, Arber and Parkin should 

 be Arber and Thomas." 



OUR ASTRONOMICAL COLUMN. 



A Brilliant Meteor on October 23. — Mr. W. F. 

 Denning writes : — " A splendid meteor was seen by Mr. 

 J. E. Clark at Purley, Surrey, on October 23, at 8h. I2^ni. 

 It shot slowly from 52°4-34° to 72°-|-4o°, and left a streak 

 for six seconds. The flight was directed from a radiant 

 in the head of .Aries, and the duration was four seconds. 

 From Lincolnshire and the eastern counties the meteor 

 must have appeared a magnificent object, and further 

 descriptions of its apparent course will be very useful tc 

 aid in determining the real path above the earth." 



Simultaneous Photographic Observations of a 

 Remarkable Meteor. — Herr Sykora, in No. 4447 of the 

 Astronomische Nachrichten, gives particulars of the path 

 of a bright meteor, of which the trail was photographed 

 at three different stations, Taschkent, Iskander, and 

 Tschimgan, on August 11, 1909. The brightness of the 

 meteor varied considerably during the flight, and as the 

 knots and outbursts are similarly shown on all three 

 photographs, it has been possible to determine the heights 

 at which they occurred. The first part of the trail, then 

 very faint, began at 112 km., and suddenly brightened 

 up at 97-7 km. ; then there were marked outbursts at 

 S,S and 85 km. respectively, with a sudden falling off at 

 S3 km. At 81 km., however, a sudden recalescence 

 occurred, and final extinction took place at 80-7 km. The 

 radiant was found to lie in the position = 44-0°, 

 5 = +56-9°- 



Two Remarkable Prominences. — No. 2, vol. xxxii., of 

 the Astrophysical Journal (September, p. 125) contains a 

 note, by Dr. F. Slocum, describing two remarkable 

 prominences photographed with the Verkes spectrohelio- 

 granh during March and April. 



One of these was remarkable for the lengthy period of 

 its existence, the other for its extreme activity and brief 

 existence. The former was first seen disappearing over 

 the western limb of the sun on March 4, but reappeared, 

 larger and transformed, on March 16 ; it was last photo- 

 graphed on April 28. On March 18 the prominence 

 extended from latitude —20° to -(-25°, and its longitude 

 was about 70° ; throughout its existence, of probably 

 about 55 days, the southern limit was practically constant, 

 but the northern limit varied considerably. The recorded 

 apparent height varied between 77,000 km. (March 18I 

 and 12,000 km. (.\pril i) ; when last photographed 

 (.April 28) the height was 61,000 km., but prominence 

 plates secured on May 11, 12, 13, and 14 showed no trace 



