May 29, 1884] 



NA TURE 



107 



with the variations of the mariner's compass, and are 

 evidently primarily due to the same cause. It is when 

 the aurora is present that they acquire extraordinary 

 energy, and change their direction and intensity with great 

 rapidity. Their effects are then observable simultaneously 

 over the whole globe. They interfere seriously with the 

 transmission of telegraph messages. 



They have been studied and examined with great care 

 in England. The eminent engineer, Mr. W. H. Barlow, 

 F.R.S., was the first in the field, and his paper before 

 the Royal Society in 1846 has scarcely been improved 

 upon or added to. The late C. V. Walker was an incessant 

 observer, and sent several papers to the Royal Society. 

 Varley added considerably to our knowledge, and there 

 are several papers by Mr. Preece, F.R.S., on their be- 

 haviour. The latter remarked that in the great storm of 

 January 31, 1881, the currents acquired an electromotive 

 force of '3 volt per kilometre of earth surface and an 

 intensity of 30 milliamperes — currents far stronger than 

 those used for telegraphy. The Proceedings of the Society 

 of Telegraph Engineers contain several interesting com- 

 munications from Adams, Dresing, O. Walker, W. Ellis, 

 Saunders, and others. It was warmly discussed at the 

 Congress of 1 88 1, which decided (1) that certain short lines 

 in each country, independent of its general telegraph system, 

 should be exclusively devoted to their study ; (2) that long 

 lines, particularly those underground, should be utilised 

 as frequently as possible for the same purpose, — lines N. 

 and S. and E. and W. being taken by preference, and 

 •one day per week — Sunday — being simultaneously em- 

 ployed for the purpose. 



It was also suggested that during the year 1S83 the 1st 

 and 15th of each month should be taken for separate 

 and careful observation. These resolutions have been 

 faithfully carried out in Paris, and M. Blavier's work is 

 the consequence. They have also been followed with 

 great advantage in Germany and in Russia. 



Permanent wires at right angles to each other have for 

 many years been fixed and used in Greenwich, but the 

 •observations have not been systematically published, 

 though the records are photographically printed. 



M. Blavier has, since September 1S83, organised a very 

 •careful system of automatic observation, by employing a 

 ■clockwork apparatus similar to that designed by M. 

 Mascart to register simultaneously the three components 

 ■of terrestrial magnetism. He uses the dead-beat galvano- 

 meter of Deprez and d'Arsonval, shunted so as to meet 

 the cases of all currents. As the chief point to be deter- 

 mined is the difference of potentials at the ends of a 

 ■circuit, M. Blavier made the resistance of each long 

 circuit examined equal to 10,000", and each short circuit 

 1000". The ordinates of the curve traced give indirectly 

 the electromotive forces present. His excellent memoir 

 contains a series of these curves, and very instructive they 

 are. A complete lunar month from February 28 to 

 March 28 is given. Observations were taken on aerial 

 and underground wires. The general direction of maxi- 

 mum electromotive force in France is N.W. — S.E., making 

 an angle of 56' with the magnetic meridian. M. Blavier 

 concludes from the deflections of the needles that the dis- 

 turbances of the magnetic elements are due to accidental 

 electric currents circulating in the higher regions of the 

 atmosphere although the earth currents circulate in the 

 crust of the globe. He favours De la Rive's theory of the 

 aurora borealis as being due to the circulation of elec- 

 tric currents in the higher regions of the atmosphere, in 

 support of which he mentions several atmospheric effects 

 well recorded as simultaneous with earth currents, such 

 as intense scintillation of the stars observed by Montigny, 

 and tempests. He associates earth currents with trade 

 winds, and thereby indirectly with the sun. 



Altogether M. Blavier's brochure is very ably written 

 and a credit to the department of which he is such an old 

 and distinguished member. 



NOTES 

 The French Minister of Education and the Fine Arts has pro- 

 posed to place at the disposal of M. Pasteur, for the prosecu- 

 tion of his scientific experiments, a large domain situated at 

 Villeneuve-Etang, which belongs to the State. 



Colonel Donnelly has been appointed Secretary and 

 permanent head of the Science and Art Department of the Privy 

 Council. 



The Paris Academy of Sciences has nominated M. Cailletet, 

 the inventor of the apparatus for the liquefaction of gas, a Mcmbrt 

 libre in place of the late M. du Moncel. The Academy has 

 appointed a Commission of six members to prepare a list of 

 candidates for the office of Perpetual Secretary. 



The death is announced of M. Bontemps, the author of several 

 volumes on pneumatic telegraphy, and engineer to the French 

 Government for the construction of the Paris system. 



A committee has been formed at Alais (Gard) for erecting 

 a statue in that city to M. Dumas. A committee will also be 

 established for the erection of a statue to M. Wurtz in Paris. 



The election of Dr. C. S. Roy to the new Professorship of 

 Pathology at Cambridge augurs well for the scientific develop- 

 ment of the rapidly-increasing medical school of that University. 

 Dr. Roy's work, both as George Henry Lewes Scholar and as 

 Professor-Superintendent of the Brown Institution, has, it is well 

 known, been of the highest merit and promise. 



The conVi rsazione of the Institution of Civil Engineers takes 

 place to-night at the South Kensington Museum. 



We are pleased to learn from a correspondent that the Natural 

 History Department of the University of Edinburgh lias undergone 

 remarkable development during the last six months. Two years 

 ago it had no lecture-room, and only one small room serving both 

 as museum and laboratory. Now the old chemistry class-room, in 

 which graduations and other ceremonials used to be held, and which 

 is still the largest class-room in the University, has been handed 

 over to the Professor of Natural History. There has not been time 

 to have the class-room reseated, but the comfort of lecturer and 

 students has been cared for in a still more important way, viz. 

 by the erection of a ventilating fan, which changes the air 

 several times every hour. The great demand for practical teach- 

 ing which marked Prof. Ewart's advent to Edinburgh could only 

 then be met with by resoi ting to a remote corner of the College 

 buildings. Now the practical work is carried on in a splendid, 

 beautifully decorated, well-lighted hall — a dingy museum in Jame- 

 son's time, but now capable of accommodating about 1 30 men 

 at a time. In addition to this laboratory there is an adjacent 

 smaller work-room for advanced students. A series of tanks 

 is in process of erection in the lower room, which corresponds 

 in size to the large laboratory, and which it is intended to con- 

 vert into a laboratory provided with all the necessary apparatus 

 for studying the life-history and development of marine organ- 

 isms. When the other rooms which formerly belonged to the 

 Natural History Department are added, the arangements for 

 teaching zoology in Edinburgh will be alike complete and 

 satisfactory. 



We understand that the University of St. Andrew is about to 

 approach the Government with the view of obtaining funds fcr 

 extending the Natural History Museum and at the same time for 

 providing a marine laboratory within the walls of the University, 

 while the more practical work of hatching, &c., which the 

 Fishery Board for Scotland is carrying on will lie provided for 



