April 25, 1901] 



NATURE 



625 



Note on Photographing Aerial Ripple Mark. 



Fig. 3 is reproduced from a photograph which I took of soine 

 remarkable ripple clouds near Bournemouth, on August 5, 

 1900, at about 5.15 p.m. The camera was pointed south ; the 

 sun, of course, is on the right, and the shadow of each cloud 

 can be seen on the right-hand edge of the next one. These 

 clouds were drifting rapidly to the east (left), the breeze at the 

 ground level blowing towards the same direction. Ruskin 

 wrote ^ 'ong since of vapour " falling into ripples like sand." 

 The general likeness is indeed striking, but the differences of 

 detail are also noticeable, which is not to be wondered at, seeing 

 that the cloud ripples are not the counterpart of the rippled 

 sand, but of the whirling water between the sand ridges. How 

 then shall we see the form of the a>.-rial ripple mark where there 

 is only blue sky? Simply by reproducing our photograph as a 

 negative (Fig. 4). With this compare Fig. 5, an ordinary (posi- 

 tive) view of the wave-formed ripple mark of the strand, taken 

 at Montrose, N. B., March 1900. Note the similarity of the 

 sharp-topped ridges of still air, between the revolving cores 

 where the clouds are, to the knife-edged ridges of the sand. 

 But most remarkable of all is the precise correspondence of the 

 confluence of ridges, wherever the wave-lengih of the ripple 





Fig. 5. — Ripple mark of the strand. Photograph taken at Montrofve, N.H., March 10, i 00. 



mark is about to change per sal turn (for the wave-length of 

 ripple mark increases in "multiple proportion," three ridges 

 merging into two). And here our sky photographs are superior 

 to, and throw light upon, our sand ripple mark photograph, for 

 the latter had to be taken when the rippling action had ceased 

 and the troughs were no longer filled with whirling water. Fig. 

 3, however, indicates what is going on where the ripple ridges 

 are being merged, for the lights and shadows of the cloud 

 indicate the activities of the working parts of the system. The 

 rippled cloud here photographed, and consequently the true air 

 ripples also, are symmetrical. This is not always the case ; the 

 clouds are often opaque (thick) at one edge and transparent 

 (thin) at the other. In this case the form of the aerial ripple 

 mark must be more like that of current mark, of aeolian sand 

 ripples and of tidal sand ripples. The likeness between cloud 

 negative and sand ripple positive would be more striking but 

 for the circumstance that we look up at the clouds and down at 

 the sand. This makes the perspective different in the two. 

 The real resemblance is best seen when separate prints are 

 handled, one or other pf which being inverted the perspective 

 becomes similar in both. 



. ^ Madem Painters, vol. v. part 7, chap. i. 



NO. 1643, VOL. 63] 



UNIVERSITY AND EDUCA TIONAL 

 INTELLIGENCE. 



Cambridge. — A meeting of members of the Senate and 

 others interested in the proposal to make some acknowledgment 

 to Prof. Liveing for his valuable services to science and to the 

 University will be held in the combination room of St. John's 

 College on Saturday next, April 27, at 2.30 p.m. 



Mr. Randolph Morgan, of Philadelphia, has given the sum 

 of 200,000 dollars to the University of Pennsylvania for a new 

 physical laboratory. 



From the Catalogue of the University of Cincinnati, for 

 1900-1901, we see that the total endowment of the University 

 amounts to 3,357,308 dollars, or nearly 700,000/. The latest 

 large donation was in the year 1899, when Mr. David Sinton 

 gave the University 100,000 dollars upon the condition that the 

 income derived therefrom .should be used in maintaining the 

 Academic Department. The University has an observatory 

 well equipped for carrying on astronomical work The obser- 

 vatory is at the present time co-operating with the International 

 Geodetic Association in the determination 

 of tlie variation of latitude. 



Lord Curzon, Viceroy of India, visited 

 on Tuesday the Mahomedan Anglo- 

 Oriental College, which was founded at 

 Aligarh by Sir Syed Ahmad in 1875 with 

 the view of affording Mahomedan youths 

 an opportunity of gaining a first-class edu- 

 cation under English professors. A marked 

 success has .since been obtained, the 

 Nizam and all the Mahomedan notables 

 affording liberal support. Alluding to the 

 desire of Mr. Beck, the late principal, who 

 devoted his life to the College, to expand 

 the institution into a residential University, 

 the Times reports Lord Curzon to have 

 said that the project had reached the ears 

 of the late Queen, who inquired most sym- 

 pathetically about it. Lord Curzon warned 

 his hearers that they would never get from 

 a University consisting of little but exam- 

 ining boards that lofty ideal of education, 

 the sustained purpose and the spirit of 

 personal devotion associated with the his- 

 toric Universities of England, and also 

 produced in some measure by the ancient 

 Universities of Islam. 



The reality of the competition between 

 School Board classes and Technical Insti- 

 tutions in some places is clearly ex- 

 emplified by the following extract, from 

 the latest Report of the Governing Body 

 of the Goldsmiths' Institute, New Cross 

 — in every respect an excellent institution, 

 where thorough instruction is given in science and technology. 

 "The Governors in their last Report drew attention to the 

 decline in the number of students attending certain classes. 

 This decline began in 1898 (down to that year the class 

 entries lad been uniformly progressive), and was mainly 

 due to the extension of the Free Evening Continuation 

 Schools of the London School Board, and particularly to certain 

 special centres which have been opened close to the Institute. 

 It will be sufficient on the present occasion to state that the 

 same causes still operate to check the natural growth of the 

 classes affected." Reference has been made (p. 553) to the 

 recent decision in the Court of Appeal that School Boards 

 cannot legally support classes of this character or science schools 

 out of the rates, but it has not yet been decided whether this 

 ruling will be accepted. The foregoing extract emphasises the 

 necessity for finally deciding upon the scope or area of influence 

 of the various educational authorities, and so giving our 

 educational system an organic structure in which each part hsis 

 clearly defined work to do. ...,,;. ,. ; , t .,! .a.,. < 



A MEETiNGof the Agricultural Education Comrhiftee'wks'held 

 on Tuesday, Sir William Hart Dyke presiding.' The exectitive 

 committee reported that the two subjects most urgently r^iquiring 



, .! ..i. v/ ,^|iO t .Oi? 



