August 26, 1909] 



NATURE 



267 



the standardisation of lathe and planer tools on a large 

 scale. A central tool-dressing plant has been established 

 recently at the Philadelphia Navy Yard, which supplies 

 ■high-speed lathe and planer tools to all navy yards on the 

 Atlantic coast. These tools are forged, treated, and ground 

 to standards. Each of the various yards is equipped for re- 

 grinding the tools until they require re-dressing, when 

 they are returned to the central tool-dressing plant at 

 Philadelphia for replacement by newly dressed tools. The 

 advantages of this system are that all yards are equipped 

 with tools of standard shapes and of uniformly high 

 •quality, and as the forging, dressing, and grinding of tools 

 are done in large lots, substantial reductions in cost result. 



The necessity for keeping records of the steam con- 

 sumption in the various prime-movers in use in large 

 factories and generating stations has given a stimulus to 

 the development of means of measuring and recording 

 .automatically the flow of water. In the Lea water- 

 recorder, illustrated in Engineering for August 13, 

 advantage is taken of the accuracy of the Thompson 

 V-notch, the magnitude of the angle of the notch being 

 ■selected to suit the flow. The recording arrangement 

 •consists essentially of a float having a vertical rod attached 

 to it ; a rack on this rod gears with a pinion fixed to the 

 spindle of a horizontal drum. The angle of rotation of 

 this drum will therefore be proportional to the head of 

 water over the notch. A spiral wire coil or screw thread 

 is wound round the drum, and has a contour similar to 

 the curve of flow for the notch, this curve being plotted 

 with head for abscissa and gallons or pounds per hour 

 for ordinates. A bar capable of sliding parallel to the axis 

 of the drum is actuated by the spiral on the drum, and 

 has an arm carrying the recording pencil. The movement 

 horizontally of the pencil will therefore be a measure of 

 the quantity of water flowing per hour. The record is 

 made on a chart wrapped round a drum which is clock- 

 driven ; hence the total flow in a given time is easily 

 ascertained by means of a planimeter. The makers are 

 the Lea Recorder Company, 28 Deansgate, Manchester. 



The tenth edition of Messrs. Townson and Mercer's 

 catalogue of scientific apparatus for physical laboratories 

 should prove of service to science masters and others. The 

 volume runs to 413 large pages, and contains well-illus- 

 trated information of a great variety of instruments designed 

 to be of assistance in giving instruction in all branches 

 of physics. Some parts of the catalogue, with their full 

 descriptions and well-executed drawings of important pieces 

 of apparatus, partake of the character of a practical text- 

 book of physics. Teachers in charge of physical labora- 

 tories should see that a copy of the catalogue is added to 

 their works of reference. 



We have received from the Geographical Model Works, 

 Middlesbrough, a photograph of a hypsometrical model 

 of the district of Ingleborough, near Settle, by Mr. J. 

 Foster Stackhouse. The model is said to be correct within 

 2 feet of the actual district dimension at every part. The 

 area covered is 42 square miles, and the horizontal scale 

 6 inches to a mile. Vertically, the measurements are 

 one-sixteenth of an inch to every 25 feet. The model is 

 built up of a series of ninety-four layers of cardboard, and 

 between 500 and 600 pieces were used in its formation. 

 The weight of the model in its complete state is above 

 a hundredweight and a half. Accurate full-size copies of 

 the model are now available, and particulars concerning 

 them may be obtained on application to the oflices of the 

 Geographical Model Works at Emerson Chambers, 

 Blackett Street, Newcastle-on-Tyne. 

 NO. 2078, VOL. 81] 



OUR ASTRONOMICAL COLUMN. 



Comet 1909b (Perrine's, 1896 vii.). — The re-discovery of 

 Perrine's, 1896 vii., comet by Herr Kopff is confirmed by 

 a notice in No. 4347 of the Astronomische Nachrichtcn, 

 where it is stated that perihelion passage should occur 

 about October 31-35 (Berlin M.T.). This comet, according 

 to Herr Ristenpart, passed through perihelion for the first 

 time since its discovery in 1896, in .\pril, 1903, but, owing 

 to its small angular distance from the sun, was not found 

 at that return. According to an ephemeris given by Prof. 

 Kobold in No. 4348 of the Astronomische Nachrichtcn 

 (p. 62, ."Xugust 18), the position of the comet on .August 26 

 will be a = oh. 4g-3m., 5 = -1-42° 35', and it is travelling 

 in a direction parallel to, and slightly north of, the line 

 joining v and 51 Andromeda; since its discovery on 

 August 12 the magnitude has increased 0-5. A photograph 

 of this object was obtained at Greenwich on .\ugust 14. 



The Recent Perseid Shower. — Further observations of 

 the recent display of Perseids are published in the York- 

 shire Weekly Post for August 21 by Mr. J. H. Elgie, of 

 Leeds. A number of bright meteors was seen by him, 

 between 11 p.m. and midnight, on August 11, and he 

 gives the positions of the limits of their tracks. ^ The 

 brightest object seen appeared at 11.30, and, increasing in 

 brightness, travelled from 210°, -1-35° to 222-5°, +10°. A 

 number of the meteors observed appeared to radiate from 

 a small group of stars which includes S and { Draconis. 

 A party of four observers at Sandfield, Moor Allerton, 

 saw 105 meteors between iih. and iih. 45m. p.m. on 

 August II, and one of the party, Mr. J. C._ Jefl'erson, 

 considers it the finest display he has seen since 1866. 

 .Another observer, Mr. E. Hawks, of Leeds, recorded 175 

 meteors between 9 p.m. on August 11 and dawn on 

 .August 12. 



The Spectroscopic Binary (3 Orionis. — The radial 

 velocity of Rigel was first determined at Potsdam in the 

 years 1888-91, and variability was suspected, but the 

 measures were not sufliciently definite to confirm the 

 suspicion. Similarly, Frost and Adams obtained a range 

 of about 8-5 km., and Campbell and Curtis suspected one 

 of 10 km., but in neither case were the results considered 

 sufiicientlv definite to affirm the variability of the velocity. 

 Results iiow published, by Mr. J. Plaskett, in No. i, 

 vol. XXX., of the Astrophysical Journal (July, p. 26), show, 

 however, from 275 plates taken on fifty-five nights _ in 

 1908-9, that the star is probably a binary, with a period 

 of velocity-variation of about 21-90 days. There is, further, 

 a variation of amplitude which suggests the interference 

 of a third body, and may account for the difficulties 

 encountered by the previous observers, but more evidence 

 must be obtained before this can be considered certain. 



The elements now published give the eccentricity as 

 0-296 + 0-059, the range of velocity as -1-26-09 '^"''- '° 

 + 18-55 km., the velocity of the sj'stem as +22-616 + 

 0-158 km., and the length of the semi-major axis of the 

 orbit as 1,108,900 km. These results are based on the 

 measures of the three lines Mg \4481, He A 4472, and 

 H7 \4341. 



Ephemeris for Comet 1909a (Borrelly-Daniel). — .An 

 ephemeris for comet 1909a is published by Dr. M. Ebell in 

 No. 4347 of the Astronomische Nachrichten (p. 42, 

 .August 13). As the present brightness is given as 0-07, 

 that at discovery being taken as i.o, it is unlikely that 

 this object will be observed again except with the largest 

 telescopes or by photography. 



Maximum of Mira, 1908. — Mr. Naozo Ichinohe, having 

 observed the magnitude of Mira Ceti during the period 

 which included the last three maxima, publishes the results 

 of his observations in No. 4346 of the Astronomische 

 Nachrichten, the measures made during the period 

 October, 1907, to February, 1909, being given in detail. 

 The following table shows the observed dates of, and 

 magnitudes at, the maxima, and compares the dates with 

 those calculated bv Guthnick : — 



