262 



NA TURE 



[December 30, 1909 



other plate. The effect of the light of the sky or of 

 twihght may thus be ehminated, and the light of the 

 comet compared with that of a star of known magnitude 

 spread over a standard area. The two photographs may 

 also be compared directly with a suitable photometer. 



Messrs. Barnard and Frost, having also the benefit of 

 Mr. Parkhurst's opinion, suggest as an alternative and 

 possibly better method the extra focal use of a single 

 camera. The intensity of the extra-focal cometary image 

 could be reduced to the focal plane as accurately as for 

 the star images. The relative values on different nights 

 would always be correct. 



Useful suggestions for the photometric observations of 

 the comet may be derived from a paper by Dr. Rosenberg 

 upon photometric observations of the Morehouse comet, 

 contained in the Astrophysical Journal for November. 



The polarisation, if any, of the comet's tail may best 

 be studied by photographs taken with a camera having 

 a double-image prism placed over the lens. The prism 

 should be turned so that the two images are perpendicular 

 to the direction of the sun. The two images of an un- 

 polarised object should be alike if the correction for colour 

 is the same for both, otherwise it will be necessary to 

 take a second photograph, turning the prism 180°. If the 

 light is polarised, one image may be fainter than the other, 

 as in similar photographs of the solar corona. Measures 

 may be made as described in the preceding paragraph. 



Bands will doubtless be seen if the comet is examined 

 by means of a Savart's polariscope or similar instrument, 

 but it is, in that case, difficult to distinguish between slight 

 polarisation of the comet and the strong polarisation of 

 faint sky-light. 



Minor Notes. 



The following titles may be specified as minor matters 

 not included above, but which may in some circumstances 

 become of importance, viz. : — • 



The head of the comet should be carefully examined for 

 traces of phase. Possible disturbances may be found in 

 the comet, due to its close approach to Venus on Mav i 

 and to the earth on May 18. A transit of the earth 

 through the comet's tail is possible at or near the latter 

 date, and, if such should occur, a meteoric shower should 

 be looked for and observed with reference to a determina- 

 tion of the meteoritic particles, their frequence, size, &r. 

 Resultant disturbances, of the electric potential of the 

 earth's atmosphere are possible, and the cooperation of 

 meteorological observers, and especially of national weather 

 bureaus, is earnestly desired in this connection. 



Although the amount of refraction experienced by light 

 in transit through a comet is known to be very srnall, it 

 seems desirable to make investigation of the matter photo- 

 graphically with long-focus telescopes. The position of a 

 sufficiently bright star near the nucleus, or in the brightest 

 part of the edge of the tail, should be referred to a group 

 of more distant ones, and the resulting position of the star 

 compared with that resulting from another plate exposed 

 after the comet has left the star. 



THE HEADMASTERS' COXFERENCE. 



T' 



■"HE headmasters of sixty of the leading public schools 

 met at the Leys School, Cambridge, on December 22 

 and 23. On the first day the chief matter discussed was 

 the work of the Public Schools' League for Imperial Land 

 Settlement in the Overseas Dominions, which was strongly 

 supported by the Rev. Dr. Gray (warden of Bradfield 

 College). Under the auspices of the committee, approved 

 boys are to be' sent to a Canadian farm after completing 

 their school career. A course at an agricultural college 

 is to follow a year's practical training on the farm, and 

 it is hoped that the public schools will assist the supply 

 to the dominion of " men of character, intelligence, and 

 energy, possessed of a little capital, who will settle down 

 seriously and will assist in bringing under cultivation the 

 immense areas of land at present untouched." The con- 

 ference pledged its support to the establishment of a central 

 oflice in London for the permanent work of the league. 

 Later in the dav the meeting asked for fuller recognition 

 of English in the university examinations for admission. 

 All the speakers emphasised the importance of the subject, 

 NO. 2096, VOL. 82] 



which was no longer regarded as something for a spare 

 hour ; not a few were of opinion that to add English to 

 the entrance examinations would be the worst service they 

 could do to the cause. Fear was expressed lest a set 

 period or figure in literature might be made compulsory, 

 and the comments of some speakers upon the university 

 examinations were decidedly caustic. 



On the second day the meeting debated the report of 

 the curriculum committee as to a scheme of studies for 

 schoolboys from the age of nine to about sixteen. The 

 conference passed, practically unanimously, the three 

 following resolutions : — 



That this conference approves the principle laid down 

 in the curriculum report of the committee that a boy 

 should not be allowed to begin Greek until the foundations 

 of Latin and French have been securely laid and he has 

 received systematic training in English. 



That it is essential to give such a definite position to 

 English and French in the entrance scholarship examina- 

 tions that these subjects may not be sacrificed to a pre- 

 m.ature study of Greek ; that this meeting be urged to take 

 such steps as will ensure full consideration of the nature 

 and results of the mathematical teaching of boys from 

 nine to sixteen ; and that it be referred to a subcommittee 

 to consider and report to this meeting. 



That a special meeting of those headmasters who are in 

 favour of the recommendations of the committee be 

 summoned in the early part of next year to take steps to 

 give practical effect in their own schools to the proposals 

 made bv the committee, and with this object in view that 

 the secretary be instructed to send a circular to the 

 members of the conference in the third week of January 

 asking whether they are generally in favour of the recom- 

 mendations of the committee, and, if so, whether they 

 will be prepared to meet in London on a certain date in 

 February or March. 



There were several points in the report which were not 

 dealt with in the resolutions, e.g. the committee is con- 

 vinced that German should be excluded from the prepara- 

 torv school. At the present time the two languages must 

 be Latin and French, in order to provide a basis of educa- 

 tion preparatorv to classical and modern sides. Dealing 

 with mathematics, the committee reports that in some cases 

 the attempt is made to cover too much ground for the 

 average boy, yet in others there is a danger that mathe- 

 matics mav be sacrificed entirely. 



Althoueh reformers will wish that the headmasters had 

 gone further, it is a matter for congratulation that this 

 year's conference exhibited a prO£*ressiv^ spirit alike in 

 resolutions and in individual speeches. Not only did the 

 meeting recognise the relation of the public schools to the 

 Emnire, but it deprecated early specialisation in Greek, 

 encouraged the advance of English studies, and adopted 

 the principle of differentiating curricula to suit varying 

 can.acitv. Above all, the headmasters acknowledged the 

 obligation to give practical effect to the opinions which 

 thev expressed in conference. Perhaps we may not have 

 to wait manv years before drawing, nnture-studv, music, 

 and handwork are accorded the status of essential subiects 

 in the preparatory curriculum. G. F. D. 



W./ITER SUPPLY IN THE UNITED STATES.^ 

 TT is an obvious truism that water is the commonest and 

 most plentiful substance in nature. Oceans, seas. 

 Lakes, rivers, floods, and streams innumerable testify to its 

 universality, and its indispensability is no less manifest. 

 Whenever man penetrates into virgin territory, his first 

 care is to find water ; wherever civilisation sets up her 

 ultimate standard of health and comfort, she establishes 

 and secures an efficient water supply. Water is the embodi- 



1 Water Supply Paper; ■ No. 224 Some Desert WaterinE Places in 

 South-eastern California and South-western Nevada. By Walter C. Men- 

 denhall. Pp. q8. 



No. 22S. Water Supply Investigations in the Yukon-Tanana Region, 

 Alaska. 1907 and iQc8. By C. C. Covert and C. E. Ellsworth. Pp 108. 



No 230. Surface Water Supply of Nebraska. By J. C. Stevens. 

 Pp. 251. 



No. 231. Geoloev and Water Resources of the Harvey Basin Region, 

 Oreeon. By C.erald A. Warine. Pp. ot,. 



No. 2.^4. Papers on the Conserva'ion of Water Resources. Pp. q6. 

 (Ignited States Geological Survey. Washington ; Government Printing 

 Office 1909) 



