324 



NATURE 



[November 20, 19 19 



The main portion of the experiment hinged upon 

 Ascension. The umbral cone passed from west to 

 east, and was expected to affect in succession the 

 strength in which signals were received at such 

 stations as Demerara, Jamaica, the stations on the 

 coast of the United States and Canada, stations in 

 Ireland, England, France, Italy, the Mediterranean, 

 and Egypt. 



The shadow of the moon struck the earth first at 

 dawn on the coast of South ."Xmerica and swept across 

 the continent in the course of half an hour, at first 

 with enormous velocity, but losing speed as the 

 Atlantic Ocean was approached. .About the middle 

 of the ."Vtlantic Ocean and near the equator the speed 

 of the shadow was about one-third of a mile per 

 second. On crossing the African continent from the 

 Gulf of Guinea to the Mozambique Channel the speed 

 gradually increased, and the eclipse finished at sunset 

 near Madagascar. The effects of the moving shadow 

 were investigated under three heads : — 



fi) Strays. 



(2) Signals not crossing the denser parts of the 

 shadow. 



(3) Signals crossing through or near the umbra. 



Slrays. 



These were bad on the day of the eclipse and on 

 the preceding day in Europe, North .'\merica, and 

 temperate latitudes on the ."Xtlantic Ocean. They 

 were very few in Central and South America and in 

 the central equatorial Atlantic. In Central America 

 the conditions were exceptional meteorologically, the 

 dav having less rain than nearlv every day of the pre- 

 ceding three weeks. The preliminary survey of the 

 results recorded throughout the part of the globe 

 reaching from Constantinople to Rio de Janeiro sug- 

 gests that there was no outstanding occurrence in 

 regard to frequency or intensity of strays that could 

 be directly ascribed to the passage of the shadow-. 



Signals not Traversing the Dense Shadow. 



Many observations were made in northern Europe 

 and .'\merica on the signals from the Azores, which 

 were arc-signals of 4700 metres wave-length. The 

 observing points extended from Berlin through Hol- 

 land, France, Italy, Spain, and Great Britain to 

 stations near the Atlantic coast of the United States. 

 There were no unusual variations in the strength of 

 the signals from the Azores. 



-Another class of experiment comes under this head- 

 ing. It was suggested bv the effect sometimes ob- 

 served at sunset or sunrise, in which the twilight band 

 when on one side of a transmitting station appears 

 to strengthen as if by reflection the waves received at 

 a station on the other side of the transmitting station. 

 In order to test whether such reflections occurred 

 during an eclipse certain stations on the south of the 

 central line of the eclipse were asked to listen to 

 Ascension, which was also south of the central line. 

 The stations at Durban and Port Nolloth (South- 

 West .Africa) found no trace of the effect, and, in fact, 

 the former concluded that the signals from .Ascension 

 were rather worse after the eclipse began. .An 

 analogous experiment on the northern side was carried 

 out bv one of the Malta stations and also at Rosvth, 

 listening to Cairo, with similar conclusions. 



KffL'cf of Signals Passing across the Central Line. 



.Arrangements were made for the transmission of 

 signals from the Darien station of the Panama Canal 

 zone, and several stations in South America attempted 

 to receive the signals. The report from the Falkland 

 Islands has not yet come to hand, and the other 

 stations in South .America did not succeed in picking 

 NO. 2612. VOL.. 104] 



up the signals. The only observation made on the 

 earlier stages of the eclipse are those of Demerara 

 listening to .Ascension. Fluctuations in signal 

 strength are reported, but no steady increase or de- 

 crease in strength. Ships at sea within the penumbra 

 report a strengthening of all signals during the eclipsi-. 

 The most striking results were obtained at some f)f 

 the stations in France, Malta, and Teneriffe. .At 

 Meudon and at Rousillon the signals from .Ascension 

 were received practically only while the eclipse was in 

 progress. Both Malta and Teneriffe found that the 

 eclipse produced a great improvement in the strength 

 of signals. On the other hand, Durban was unable 

 to pick up Cairo, though this is usually possible, but 

 .Aden was picked up with greater intensity than 

 normal. On the whole, the records show that the 

 improvement in signal strength reached its highest 

 value long before the umbra intervened between the 

 stations, and this value persisted after the umbra had 

 passed ; that is to say, if ionising processes are the 

 cause of the change in the strength of signals, the 

 results indicate that the processes are practically fully 

 accomplished in a given region of the air before the 

 arrival of the umbra at that place, so that there 

 appears to be nothing left for the umbra to do in 

 the few minutes of complete shadow it brings. 



The thanks of the committee are due especially to 

 the Admiralty for arranging that their stations at 

 .Ascension and the .Azores should transmit the nec?s- 

 sarv signals, and also to the .American Government 

 for making similar arrangements regarding Savville 

 and Darien. Thanks are due also to the .American, 

 French, and Italian Governments, the .Admiralty, the 

 War Office, the .Air Ministry, and Marconi's Wire- 

 less Telegraoh Co., Ltd.. for undertaking observations 

 and recording the variations in signal strength. 



UNIVERSITY AND EDUCATIONAl 

 INTELLIGENCE. 



Cambridge. — The council of the Senate reports that, 

 after consultation with Sir W. J. Pope, it is con- 

 sidered desirable to establish a professorship of 

 physical chemistry, the stipend of loooJ. per annum 

 to be furnished out of the benefaction of the British 

 Oil Companies. 



The General Board of Studies has recommended 

 the appointment of Mr. .A. .Amos, of Downing College, 

 as University lecturer in agriculture. This appoint- 

 ment is proposed in view of the new scheme of study 

 in agriculture, extending over three years, and the 

 large increase of students in the department of agri- 

 culture. 



Glasgow. — President Poihcar^ was installed as 

 Rector of the University on November 14, and de- 

 livered his rectorial address in English to an assembly 

 of four thousand students and other members and 

 friends of the University in St. .Andrews Hall. The 

 proceedings were conducted in admirable order, the 

 students recognising that M. Poincare was not only 

 their Rector, but also the honoured chief of an .Allied 

 State, visiting this country as his Majesty's guest. 

 The Vice-Chancellor, Sir Donald Ma^Alister, K.C.B., 

 conferred on him the degree of LL.D. honoris causa 

 before the installation. The Vice-Chancellor wore the 

 Cross of Commander of the Legion of Honour, with 

 which the President had privately invested him before 

 the public ceremony. 



.At a meeting of the l^niversity Court hold after- 

 wards, the Rector in the chair, a number of important 

 gifts to the University were announced. .Among them 

 were contributions amounting to about 2o,oooZ. for 

 the erection of a memorial chapel in commemoration 



