September 22, 1922] 



SCIENCE 



329 



liam, who was afterwards also to contribute to 

 the astronomical fame of the family. An old 

 thatched barn, which Hersehel used as a work- 

 shop, was visited next, and the party after- 

 wards went through Upton Court, where his 

 wife's first husband, John Pitt, lived. It be- 

 longs to Lord Harewood, and has been for some 

 time untenanted. In the afternoon the visitors 

 were welcomed to Observatory House by Miss 

 Hersehel. There they saw many interesting 

 personal relics — some in the house itself, some 

 in an adjoining cottage which has 'been made 

 into a little museum, and some in the garden. 

 Against the back wall of the garden, embow- 

 ered in foliage, rests a section of Herschel'.s 

 great telescope, 10 feet or 12 feet in length. 

 A circular ridge on the lawn marks the place 

 where the telescope formerly stood. In the 

 hall of the house is one of two mirrors which 

 were cast for the big telescope. The mirror and 

 tube of the smaller telescope which Sir John 

 Hei-schel took to the Cape to survey the heavens 

 of the southern hemisphere were also shown. 



At luncheon, which was served at the Old 

 Crown Hotel, at one time part of the property 

 of Sir William Hersehel, the Reverend Sir 

 John Hersehel said that the great work of Sir 

 William Hersehel at Slough was his investiga- 

 tion of the structure of the heavens. He put 

 . forward the view that the whole visible universe 

 was like a couple of soup-plates put face to 

 face. That theory, he believed, still held the 

 field. Another great discovery was that of 

 nebula?. Hersehel at first thought they could 

 be resolved into separate stars, but afterwards 

 came to the conclusion that in certain eases 

 these dull, fuzzy things were a shining fluid. 

 That some of the nebulas were resolvable into 

 stars was proved later by Lord Rosse, and the 

 hypothesis of the shining fluid was confirmed 

 many years later by Huggins. Sir William 

 Hersehel was much before his age in his specu- 

 lations. Though they fell into discredit for a 

 time, he had since come into his own again and 

 had been found to have made very few mis- 

 takes. 



Sir Frank Dyson said he thought what Sir J. 

 Hersehel had said about Sir William Hersehel 

 was true. He was undoubtedly a very great 

 man. In addition to the wish to fathom the 

 heavens, he had the great mechanical and en- 



gineering skill which enabled him to make his 

 telescopes. He had also the prodigious enthu- 

 siasm and energy needed to carry out his big 

 surveys. 



Dr. Dreyer added further instances of Sir 

 William Herschel's clear insight. About the 

 year 1785 he announced that the sun was trav- 

 eling through space towards the constellation 

 Hercules. Though the evidence was perhaps 

 slender at the time, and nobody, he believed, 

 took serious notice of the matter, the discovery 

 was undoubted. He also first suggested the 

 "gi'indstone theory" of the Milky Way — that 

 there was a great layer of stars between two 

 parallel planes. 



THE INTERNATIONAL GEOLOGICAL 

 CONGRESS 



The twelfth International Geological Con- 

 gress was held in Belgium during the month 

 of August with a large and influential delega- 

 tion of some 500 geologists from all parts of 

 the word, except former enemy countries. A 

 number of geological excursions were organ- 

 ized covering the most interesting sections of 

 Belgium, to which a large number subscribed. 

 France was well represented by men like 

 de Mai'gerie, Lacroix, Gentil, Kilian, Bigot 

 Lory, Haug, Cayeui, Fallot, Yung and others; 

 while Switzerland had sent Lugeon and Argand, 

 both masters of tectonics. Especially interest- 

 ing was Argand's lecture on "The Tectonics of 

 Asia," illustrated with a tectonic map of the 

 Eurasian continent which no doubt marks an 

 epoch in structural geology. This synthetic 

 and clever graph of the Eurasian continent 

 contained more than 3,500 geological sections, 

 transferred in tectonic form and colors on the 

 map which served to illustrate the opening 

 public lecture of the congress. 



Spain was well represented, and Director 

 Cesar Rubio, of the Instituto Geologica de 

 Espana, with a goodly contingent of geologists 

 from the Iberian Peninsula, took part in the 

 congress. The invitation given by Spain was 

 accepted, so that the fom'teenth International 

 Congress of Geology is to be called for 1925 in 

 Spain. 



A large numlier of United States geologists 

 attended the congress. Dr. David White, chief 

 geologist of the U. S. Geological Survey, was 



