May 29, 1884] 



NA TURE 



113 



He noticed that the stars moved in ellipses every year round 

 a mean point. This fact of aberration, then, is a real thing. It 

 has been said that the angle at which the tube had to be inclined to 

 receive the weight depended upon their respective velocities, that 

 the faster the tube travelled, the greater must be its inclination, and 

 therefore the greater the angle the greater the earth's velocity with 

 reference to the velocity of light. In the case of the majority 

 of the stars what we get is an ellipse, and iu an ellipse we have 

 certain differences which have to be taken into account, the last 

 difference of all being that an infinitely elongated ellipse is a 

 straight line, and it is found that from one particular point of 

 the heavens where, in consequence of this aberrational motion, 

 the orbits of the stars round their mean places are almost 

 circular, we at last get to a point where the motion is simply an 

 oscillation of the star backwards and forwards to and from its 

 mean place ; we are dealing, in fact, with that form of the 

 ellipse when it is in the form of a straight line. When we deal 

 with an ellipse we no longer talk of the radius, but of the semi- 

 axis major, which is half the greatest length. The angle of 

 aberration of which I have spoken only amounts to 2o"'445i, but 

 though small, it is quite enough to prove that the earth does 

 revolve, and that consequently the sun is the centre of the 

 system to which the earth belongs. Now in order to show the 

 importance of physical inquiry in this matter, there is another 

 statement which must be made. If we consider this aber- 

 ration question fully, we find in it what is perhaps the most 

 perfect way of determining the distance of the sun from the 

 earth, and it will be seen that it is perfectly simple, so simple in 

 fact, that the wonder is that more attention has not been given 

 to it in our text-books. We have first the fact that the inclina- 

 tion of the tube depends upon the relative velocities of the tube 

 and falling body ; in the case of light it will of course depend 

 upon the relative velocities of the earth in its orbit and light 

 radiating from a star. Knowing this latter to be somewhere 

 abont lS6,ooo miles per second, and the aberration angle to be 

 20" and something, we can get the relation of the earth's motion 

 to the velocity of light, and it comes out to be about I to 10,089. 



Now we know that the earth completes a revolution round 

 the sun in 365^ days. If it travelled with the velocity of light it 

 would complete a revolution in 52m. S'5s. 



Again, we may say, and this is only a rough statement, that 

 the radius of a circle is 1/6 of its circumference, so that if it 

 took the earth fifty-two minutes to go round its circumference, 

 or, as we call it, its orbit, it would take 1/6 of that time to go 

 along the radius if it travelled with the velocity of light ; it would 

 therefore take 8m. 18s. Hut this radius is the distance of the 

 earth from the sun, and having this time 8m. 18s., we have only 

 to multiply the velocity of light 1 per second, by that, and we get 

 92,628,000 miles as the distance of the earth from the sun. 



J. Norman Lockyer 

 ( To be continued. ) 



THE ROYAL COMMISSION ON TECHNICAL 



INSTRUCTION 

 ■\S7E have just received from the Commission the two volumes 

 of their second Report on Technical Education. We give 

 this week the Recommendations with which the Commissioners 

 conclude their Report : — 



Having carefully considered what is desirable and practicable 

 in regard to the general and technical instruction of the various 

 classes engaged in industrial pursuits in this country, we humbly 

 offer the following recommendations, which require the inter- 

 vention of the Legislature or of public departments : — 



I. As to public elementary schools : 



(a) That rudimentary drawing be incorporated with writing 

 as a single elementary subject, and that instruction in elementary 

 drawing be continued throughout the standards. That the 

 inspectors of the Education Department, Whitehall, be respon- 

 sible for the instruction in drawing. That drawing from casts 

 and models be required as part of the work, and that modelling 

 be encouraged by grant. 



(b) That there be only two class subjects, instead of three, in 

 the lower division of elementary schools, and that the object 

 lessons for teaching elementary science shall include the subject 

 of geography. 



(V) That, after reasonable notice, a school shall not be deemed 



1 The exact value is iS 

 error of thirty-three mile 



1,380 miles according to Michelson, with a possible 



to be provided with proper "apparatus of elementary instruction " 

 under Article 115 of the Code, unless it have a proper supply of 

 casts and models for drawing. 



(d) That proficiency in the use of tools for working in wood 

 and iron be paid for as a "specific subject," arrangements being 

 made for the work being done, so far as practicable, out of 

 school hours. That special grants be made to schools in aid of 

 collections of natural objects, casts, drawings, &c, suitable for 

 school museums. 



(e) That in rural schools instruction in the principles and facts 

 of agriculture, after suitable introductory object les ; ons, shall be 

 made obligatory in the upper standards. 



(/) That the provision at present confined to Scotland, which 

 prescribes that children under the age of fourteen shall not be 

 allowed to work as full-timers in factories and workshops unless 

 they have passed in the Fifth Standard, be extended to England 

 and Wales. 



II. As to classes under the Science and Art Department, and 

 grants by the Department : 



(a) That School Boards have power to establish, conduct, and 

 contribute to the maintenance of classes for young persons and 

 adults (being artisans) under the Science and Art Department. 

 That in localities having no School Board the local authority have 

 analogous powers. 



(b) That the Science and Art Department shall arrange that 

 the instruction in those science subjects which admit of it shall 

 be of a more practical character than it is at present, especially 

 in the "honours " stage ; that payment on results be increased 

 in the advanced stages of all subjects, at least to the level of 

 those now made for practical chemistry and metallurgy, and that 

 greater encouragement be given to grouping. 



(<) That the examinations in agriculture be made to have a 

 more practical bearing. 



(d) That metallurgy, if it be retained, be divided into groups, 

 as (I) the precious metals, (2) those extracted from metallii 

 mines, as copper, tin, lead, &c, (3) iron and steel. That 

 mining be similarly divided into (1) coal and (2) metalliferous 

 mining. 



(f) That the inspection of science classes by the Science and 

 A it 1 lepartment, with a view to ascertain the efficiency of the 

 instruction, and of the apparatus and laboratories, be made 

 more effective, with the assistance, where necessary, of local 

 sub-inspectors. 



(/) That it shall not be a requirement of the Science and Ait 

 Department that payment of fees be demanded from artisans for 

 instruction in the science and art classes. 



(g) That in the awards for industrial design more attention be 

 paid by the Department, than is the case at present, to the 

 applicability of the design to the material in which it is to be 

 executed, and that special grants be made for the actual execution 

 of designs under proper safeguards. 



(//) That the limits of the building grants, under the Science 

 and Art Department, to 500/. each for schools of Art and of 

 Science should be abolished, and the conditions attached to them 

 be revised. 



(») That, in addition to the loan of circulating collections and 

 the grant of art reproductions at reduced cost, contributions be 

 made to provincial industrial museums of original examples 

 tending to advance the industries of the district in which such 

 museums are situated. 



III. Training Colleges for elementary teachers : 



(a) That the leaching of science and art in Training-Colleges, 

 and its inspection by the Science and Art Department, be made 

 efficient, and that arrangements be made for giving to selected 

 students in those Colleges greater facilities and inducements for 

 tlie study of art and science in the National Art Training School 

 and the Normal School of Science at South Kensington, the 

 Royal College of Science for Ireland, and other institutions of 

 a similar class approved of by the Government. 



IV. Secondary and technical instruction : 



(a) That steps be taken to accelerate the application of ancient 

 endowments, under amended schemes, to secondary and technical 

 instruction. 



(/') That provision be made by the Charity Commissioners for 

 the establishment, in suitable localities, of schools, or depart- 

 ments of schools, in which the study ol" natural science, drawing, 

 mathematics, and modern languages, shall take the place of 

 Latin and Greek. 



(o) That local authorities be empowered, if they think fit, to 

 establish, maintain, and contribute to the establishment and 



