Feb. I, 1872J 



NATURE 



263 



of zigzags which yield without entanglement to the very rapid 

 motion of tlie rocket — the strain on the cord being only due to 

 its inertia. As then the force required to set it in motion is 

 proportional to the weight of cord moved multiplied by its velo- 

 city, and this weight is also proportional to its weight per unit of 

 length multiplied by the velocity, the strain or tension, T = MV^ 



-^ ; the relation which we have already seen is 



necessary to the production of a stationary wave. Accordingly, 

 we find that the rope, instead of at once following the flight of 

 the rocket, rises almost perpendicularly from the box, and only 

 passes into its low trajectory at a distance of six or eight feet, 

 with a sharp irregular curve, which remains comparatively steady 

 during the whole flight of the rocket. This curve is no doubt 

 first produced in the first portion of the rope, which is "faked 

 down " on tire ground outside the box ; but it would be impos- 

 sible to see its formation, because of the smoke of the discharge, 

 even if the motion were not too rapid. 



One rather curious result of the above-mentioned conditions 

 is, that however erratic the flight of the rocket may be, the rope 

 will continue to follow through the whole track, as if the air 

 were a solid which the rocket had pierced. 



Another result is, that no lateral vibrations can be propagated 

 along a rocket line — a fortunate^condition with regard to steadi- 

 ness of flight. Henry R. Procter 



Clementhorpe, North Shields, Jan. 26 



Ocean Currents 



Prof. Everett has evidently misapprehended what I said 

 in my letter to N.\ture, January 11. Nine foot-pounds would, 

 of course, generate in a pound of matter a velocity equal to that 

 acquired by the pound falling through a space of nine feet. And 

 in reference to the deflecting power of rotation, what I meant was 

 not the amount of deflection in a given space passed over, but 

 the positive amount, say in feet, in a given time. 



Edinburgh, Jan. 27 James Croll 



ON TEACHING GEOLOGY AND BOTANY AS 

 PARTS OF A LIBERAL EDUCATION 



ON Monday, Jan. 22, one of a series of lectures on 

 Educational questions was given at the rooms of the 

 Society of Arts by Mr. J. M. Wilson, of Rugby. The 

 following may be taken as an abstract of the lecture : — 



Two points have to be considered : (i) When, if at all, 

 these Natural History Sciences ought to be introduced 

 into schools ; (2) What they should include, and how they 

 should be arranged for teaching purposes. 



The problem before schoolmasters is to adjust the 

 rival claims of the subjects which press for admission into 

 the school course, all of which may urge something in 

 their favour. These subjects have increased in number 

 and extent so that the question of rc-arrangement is press- 

 ing. For the solution at present is to admit a little of 

 all, or nearly all ; and the effect of this is to distract. A 

 wide education levels up, but also levels down, and 

 weakens, by ehminating the close study of detail, and the 

 drudgery that is essential in valuable work. It is that 

 conflict between the old theory of promise and the new 

 theory of performance ; and schools are in great danger 

 of giving less faculty than they did formerly, though they 

 give increased knowledge. 



To meet the requirements some stratification of studies 

 must be effected, so that not so many shall be followed at 

 once. Greek and Chemistry and Physics (except Me- 

 chanics), should be excluded from the elementary course, 

 which should include Latin, French, Arithmetic, and 

 Natural History. Then bifurcation should begin ; the one 

 branch leading to Greek and a mainly literary education, 

 the other to Science; both continuing Latin and English, 

 and French and History. The recognition of the bifur- 

 cation, both by the Universities and by the great schools. 



is urgently needed. Without it Science must be dwarfed 

 or excluded, and literature also suffer from the distraction 

 which is already felt at schools. The programme of the 

 reformers in education ought to include the abolition of 

 Greek as a compulsory subject at the Universities. 



By Natural History is meant what Hu.xley has intro- 

 duced to us under the word " Erdkunde." The earth, its 

 relation to sun and moon, the phenomena of day and 

 night, and seasons ; the changes going on, the activities 

 of the earth, rain, and rivers, and sea, and earthquakes, 

 and slow changes of level, and their geological effects, 

 and something also of geology proper. The teaching 

 should be based on the familiar knowledge of the boys, and 

 should extend and systematise it, and without being too 

 dogmatical, should be practical where possible. A little 

 botany, enough to teach the objects and the interests of the 

 science, and the principles of structure and classification, 

 and something of geographical distribution, may well be 

 included in the natural history of this elementary stage in 

 education. The object of the inaster should be to dis- 

 cover and train scientific ability, as well as to give scientific 

 information, and for this purpose these studies have great 

 advantages. The bearing of the experience gained at 

 Rugby on these questions was also given. 



THE SURVIVAL OF THE FITTEST 



LAST summer a discussion took place in your pages 

 on the expression, " Survival of the Fittest," and on 

 the principle it formulates. Though, as being responsible 

 for this expression, there seemed occasion for me to say 

 something to dissipate the errors respecting it, I refrained 

 from doing so, for the reason that the rectification of mis- 

 statements and misinterpretations is an endless work, 

 which it is almost useless to commence. 



In your last number, however, the question has cropped 

 up afresh in a manner which demands from me some 

 notice. A Professor is tacitly assumed to be an authority 

 in his own department ; and a statement made by him re- 

 specting the views of a writer on a matter coming within 

 this department, will naturally be accepted as trustworthy. 

 Hence it becomes needful to correct serious mistakes thus 

 originating. 



In your abstract of Prof. E. D. Cope's paper, read before 

 the American Association for the Advancement of Science, 

 I find the following sentences : — 



" This law has been epitomised by Spencer as the 

 ' Preservation of the Fittest.' This neat expression, no 

 doubt, covers the case, but it leaves the origin of the 

 fittest entirely untouched." 



There are here two misstatements, the one direct and 

 the other indirect, which I must deal with separately. 



So far as I can remember, I have nowhere used the 

 phrase, "Preservation of the Fittest." It is one which I 

 have studiously avoided ; and it belongs to a cLiss of 

 phrases for the avoidance of which I have deliberately 

 given reasons in " First Principles," sec. 58. It is there 

 pointed out that such expressions as " Conservation of 

 Force," or " Conservation of Energy," are objectionable, 

 because " conservation " implies a conserver, and an act 

 of conserving — imphes, therefore, that Energy would dis- 

 appear unless it was taken care of ; and this is an impli- 

 cation wholly at variance with the doctrine enunciated. 

 Here I have similarly to point out that the expression 

 " Preservation of the Fittest " is objectionable, because in 

 like manner it supposes an act of preserving— a process 

 beyond, and external to, the physical processes we com- 

 monly distinguish as natural ; and this is a supposition 

 quite alien to the idea to be conveyed. One of the chief 

 reasons I had for venturing to substitute another 

 formula for the formula of Mr. Darwin, was that 

 " Natural Selection " carries a decidedly teleological 

 suggestion, which the hypothesis to be formulated 

 does not in reality contain ; and a good deal of the ad- 



