March 9, 1899] 



NA TURE 



441 



ahis statement, I would say that I know of no such instance. 

 If there are cases of lines showing structure by the ordinary 

 grating, which I do not mention, it is simply that my attention 

 has not been directed to them, and I should venture to guarantee 

 that if observed by either the interferometer or the echelon, 

 they mast show the same structure — or a finer. 



I should have thought the tripling of the middle green line in 

 the case of the green mercury and cadmium lines a matter of suffi- 

 cient importance to add to those figured in Mr. Preston's paper. 



To illustrate the preceding remarks, as well as to show the 

 performance of the interferometer, I present a figure showing 

 the three types of Zeeman effect, and another showing how 

 •these results are confirmed by the echelon. 



It will be observed that there is an indication of structure in 

 the outer lines, but at this time they had not actually been 

 resolved. This has since been accomplished, as shown in the 

 oUowing figure : — 



The following is a list of the radiations thus lar examined, and 

 itheir classifications according to these types : — 



Mercury Yellow lines Type I. 



Green line ,, III. 



Violet line ,, II. 



Cadmium ... Red line ,, I. 



Green line ,, III. 



Blue line „ II. 



Zinc Red line ,, I. 



(? Cadmium) ... Green line ,, III. 



Blue hne ,, II. 



Sodium Yellow lines ,, II. 



Thallium ... Green line ,, II. (doubtful) 



Lithium Red line Broadened. 



'Hydrogen ... Red line Broadened. 



Helium Yellow line Broadened. 



Green line Type I. 



Gold Yellow line ,, II. 



Green line ,, I. 



Silver Yellow line ,, I. 



Green line ,, I. 



-Copper Yellow line ,, IV. 



Green lines ,, I. 



Magnesium ... Green line (5183)... ,, III. 



Green line(5l72)... ,, II. 



Green line (5167)... ,, I. 



-Manganese .. Green line(5340)... ,, IV. 



Argon Red line ,, I. 



Tin Red line {6450) ... „ II. 



Yellow line (5798) ,, I. 



Yellow line {5587) ,, I. 



Yellow line (5564) ,, I. 



Iron Most lines ,, I. 



Carbon Component lines ofj Unaffected. 



banded spectrum J 

 The University of Chicago Ryerson A. A. MiCHELSON. 

 Physical Laboratory, Feb. 9. 



1 Since this list was first published, decided indications of structure have 

 been noticed, especially in the broadened middle line, which under favoui- 

 able conditions appears as a group of six or seven very fine lines just 

 ■resolvable, brightest at the centre, and extending through the entire space 

 between the outer groups. Similar indications, though less distinct, were 

 traced in the outer groups. 



" Type IV. was added to include cases where a broad or complex line 

 was simplilied or narrowed in the magnetic field. This, as regards the 

 copper line and the manganese line, is true of the central line of the triplet, 

 and not (as might be inferred from the original paper) of the whole group. 



Attraction in a Spherical Hollow. 



The theorem you published in your number of January 19, 

 under the above head, may easily be deduced from the parallel- 

 ograiu of forces put in this form : 



Let aa be intensity and direction of an attractive force, ab 

 both for a repulsing force ; then the resultant of the two forces 

 in (T will be parallel and equal to ba. LaNG. 



Vienna, February 18. 



THE REPORT OF THE SELECT COMMITTEE 

 ON THE SCIENCE AND ART DEPARTMENT 

 T N the course of last year the newspapers contained an 

 ••- account of the doings of the Select Committee of the 

 House of Commons appointed to inquire into, and report 

 upon, the administration of the Museums of the Science 

 and Art Department. It was an open secret that some 

 of the members of that Committee were bitterly opposed 

 to the officials of the Department ; but however this 

 might be, all evidence tending to throw discredit was 

 very widely reported long before the Report was issued. 



The Report of the Committee in due time made its 

 appearance, and it has now been considered by the Lords 

 of the Committee on Education. The result has been 

 embodied in the shape of the following Minute, which has 

 just been distributed among the Members of the House 

 of Commons and others. 



By the Right Honourable the Lords of the Committee 

 of Her Majesty's most Honourable Privy Council on 

 Education. 



Present: — His Grace the Duke of Devonshire, K.G., 

 Lord President of the Council ; the Right Hon. Sir 

 John E. Gorst, ^LP.,Vice■President of the Committee 

 of Council on Education. 

 (i) The Lords of the Committee of Council on Edu- 

 cation consider the Second Report from the Select 

 Committee of 1898 appointed to inquire into and report 

 upon the administration and cost of the Museums of the 

 Science and .\rt Department. My Lords have also before 

 them the observations on this Report prepared in accord- 

 ance with their instructions by the Secretary of the Science 

 and Art Department, a copy of which is appended to this 

 Minute. 



(2) A reference to the proceedings of the Committee 

 shows that pp. i to 16 of the Report are based upon the 

 Chairman's draft. This part of the Report appears to 

 contain a correct statement of facts, but it is followed by 

 paragraphs, introduced as ainendments, which traverse 

 to a great extent the same ground, and contain many 

 inaccuracies and some inconsistencies. 



(3) Having regard to passages which appear to reflect 

 on individual officers. My Lords desire to emphasise the 

 fact that they alone are responsible to Parliament for the 

 administration of the Museums, and to declare that their 

 directions have been loyally carried out by the staff, and 

 that they retain the fullest confidence in Sir John 

 Donnelly and his colleagues. 



(4; They regret that the Committee should have 

 insinuated in their Report that officers have been 

 appointed because of their relationship to members of 

 the staff, and have Ijeen dismissed because of the evi- 

 dence they gave to the Committee. Such insinuations 

 are devoid of any foundation in fact. 



By order of the Committee of Council on Education. 



T' 



SCIENCE AT LIVERPOOL. 

 HE Lord Mayor of Liverpool is to be congratulated 

 upon a new departure. The Municipal authorities 

 of one of our most important cities have actually held 

 high festival in honour of a man of science, the occasion 

 being the award of the Rumford Medal to Prof. Lodge. 

 The Lord Mayor in the course of his speech said : 



NO. 1532. VOL. 59] 



