I40 



NA TURE 



[June 8, 1893 



ment or observation of any kind in the domain of this wonderful 

 science which would not forcibly appeal to us. Some beautiful 

 experiments with a vacuum tube concluded the lecture. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



Cambridge. — The Observatory Syndicate have prepared 

 a report with respect to the future work of the Cambridge 

 Observatory. 



They are of opinion that in the present condition of Astrono- 

 my provision must be made for photographic work, so that 

 their inquiries have been directed to the discovery of the best 

 scheme for rendering the Northumberland Equatorial available 

 in connection with the project for a photographic establishment. 

 The primary question as to the respective merits of reflectors 

 and refractors for the photographic instrument had of course to 

 be considered. On this issue there is considerable difference of 

 opinion. For producing representations of astronomical objects, 

 where great detail is required, reflectors are the most suitable. 

 But where accurate measurement of the photographic plates is 

 the object in view the balance of opinion seems clearly to show 

 that the refractor is better adapted than the reflector. As it 

 seems obvious that the work undertaken at the Cambridge Ob- 

 servatory should be based on accurate measurement the Syndicate 

 have come to the conclusion that the refractor is the photo- 

 graphic telescope that should be employed. They think it right, 

 however, to draw the attention of the University to the kindness 

 of Mr. Common who offered to make and present to the Ob- 

 servatory a suitable silvered glass mirror if it were decided to 

 employ the reflecting instrument. 



It may be well to add that the Newall Telescope is devoted 

 in the main to spectroscopic work and further that this instru- 

 ment having been made for visual observation is not adapted to 

 the special photographic work to which it is now proposed to 

 direct the energies of the Observatory. 



The scheme which the Syndicate suggest is that a new ob- 

 jective of eighteen inches aperture corrected for the photographic 

 rays be provided ; that the focal length of this should be about 

 the same as that of the Northumberland objective, for which a 

 new tube will be required ; and that the two objectives, united 

 as a pair like the present instruments at Greenwich and Oxford, 

 should be erected on a new mounting, under a new dome, in 

 the building at present occupied by the Northumberland Equa- 

 torial. 



It will be observed that, by this scheme, the Northumberland 

 objective will still be useful for every purpose for which it has 

 been hitherto employed, with the great additional advantages of 

 an excellent mounting and a good clock work. For example, 

 such observations of comets as have been previously made here 

 can be conducted under circumstances of much greater conve- 

 nience than before. As to the special work to be undertaken 

 by photography, it appears to the Syndicate that for the present 

 under the particular conditions in which work here can be con- 

 ducted there is no subject so promising as stellar parallax. The 

 Director of the Observatory desires to undertake a systematic 

 search with the aid of photography for stars which have meas- 

 urable parallax, and of course so complete an apparatus as is 

 now proposed would be available for many other researches be- 

 sides that just suggested. 



A preliminary estimate for the new telescope and mounting 

 complete makes the cost .^2450. To this must be added ;^5oo 

 for the new dome, and ;^I50 for the measuring apparatus. If 

 ;^loo be added for extras this makes a total of ^3200. There 

 is now a sum of about .1^1500 in the Special Sheepshanks Fund 

 available for the purchase of instruments. In view of future 

 contingencies, to exhaust the Sheepshanks Fund would be un- 

 advisable and indeed it would not suffice for the purchase of an 

 18-inch equatorial. As such an instrument would contribute 

 largely to the astronomical services of the Observatory the Syn- 

 dicate think that an appeal to the public for subscriptions would 

 probably be successful and such an appeal they are prepared to 

 make. 



It is therefore recommended that they be authorised to ob- 

 tain estimates and plans for a new instrument as above de- 

 scribed 



Dr. Hill, Master of Downing College, has been appointed a 

 representative of the University at the International Medical 

 Congress to be held at Rome next September. 



SCIENTIFIC SERIALS. 



American Meteorological yournal, May. — The following are 

 the principal meteorological articles : — Meteorology as the 

 physics of the atmosphere, by Prof. W. v. Bezold. This is a 

 translation by Prof. C. Abbe of the first part of an important 

 paper from Ilimmel und Erde. It describes the problems 

 which at present are the subject of theoretical investigation, 

 and points out what new problems have grown from looking at 

 observational meteorology from a theoretical point of view. 

 Duringthelastdecade attention has been chiefly devoted tothede- 

 velopmentof the so-called convection theory, which is principally 

 based on observations at the earth's surface, but which, at higher 

 elevations, is found to have defects. It has therefore become 

 necessary to try and connect this theory with that of the old 

 trade-wind theory, which for several decades has been entirely set 

 aside. More attention is required to observations made in the 

 higher regions of the atmosphere, together with the application 

 to them of the principles of general mechanics, as well as of 

 thermo-dynamics. — Charts of storm frequency, by Prof. Abbe. 

 The author has plotted in a tabular form the number of storm 

 centres that pass over each quadrangular degree between lat. 20° 

 and 49° N., and long. 99° and 63° W., deduced from the tri- 

 daily Signal Service charts, from March, 187 1, to February, 

 1S73. lis states that the chart from which the table is pre- 

 pared clearly shows that the storm tracks, which move from 

 Alberta and Assinniboin south-eastward over the t nited 

 States and then north-eastward towards the gulf of St. Law- 

 rence, describe a system of parabolic curves whose tendency is 

 to have a common point of intersection, and therefore a region 

 of maximum storm frequency, in, or to the north-west of 

 Nebraska. — Six and seven day weather periodicities, by II. H. 

 Clayton. The author, who has studied the subjects of periodi- 

 cities for several years, found a striking regularity between the 

 intervals of many of the temperature maxima of the Blue Hill 

 observations, and that almost all the maxima could be arranged 

 in such a way that they followed each other at intervals of six 

 or seven days. He thinks that, for a large part of the year, 

 forecasts of temperature, on the assumption of regular rhythmic 

 oscillations, and a knowledge of the time of their beginning 

 and ending, may be made for a week or two in advance with 

 nearly as much accuracy as they are now made by the Weather 

 liureau for thirty-six hours. 



American Journal oj Mathematics, vol. xv., No. 2. (Balti- 

 more, April, 1893). — The opening memoir is one entitled 

 " Hyperelliptische Schnittsysteme und Zusammenordnung der 

 Algebraischen und Transcendentalen Thetacharacteristiken,"by 

 II. D. Thompson (pp. gi-123). There are numerous ligures 

 and an index of contents. — On the determination of groups 

 whose order is a power of a prime, by J. \V. A. Young (pp. 

 124-178), considers in some detail groups of the order specified 

 in extension of the work on groups by Cayley {Am. J. of Math., 

 vol. i. ), Kempe (/"/^z/. Trans. , vol. clxxvii. ), Netto (Substitution- 

 entheorie, pp. 133-7), and Kronecker. The author's aim has 

 been " to presuppose no knowledge of the theory of groups on 

 the part of the reader." — The third paper, the projection of four- 

 fold figures upon a three-flat, by T. P.' Hall (pp. 179-189), is an 

 interesting contribution to the literature of higher space, and the 

 last page (190) contains a note on a geometrical theorem by 

 C. N. Little. It gives a property of a Pascal line, and a 

 Brianchon point of 6 gons formed in a specified manner. 



Wiedemann' s Annalen der Physik und Chemie, No. 5. — On 

 electrical discharges : production of electrical oscillations and 

 their relation to discharge tubes, by H. Ebert and E. Wiede- 

 mann. This portion of the work investigates the manner in 

 which the properties of the conducting circuit determine the 

 sensibility of the discharge-tube when placed in a given position 

 with regard to the terminal condenser. Among the conditions 

 thus studied were the distance between the plates of the primary 

 condenser, the D.P. in the primary spark-gap, and the fre- 

 quency of the sparks; also the influence of bridges across the 

 wire system, the D.P. required to make the tubes glow, and 

 the effects of the presence of other glowing tubes in the field. As 

 regards the last, it was found that if a glowing gas was present 

 in a portion of the condenser field the distribution of energy 

 was quite different from that in a homogeneous field ; the tubes 

 of energy were attracted towards the g.isand passed through it, 

 showing that the gas in the state of glow has a greater per- 



NO. 1232, VOL. 48] 



