90 



NATURE 



[July 20, 191 1 



experiment i- instructive as well as amusing, and it pro- 

 vides a simple means of realising the effects of colour- 

 blindness. The spectacles and wools are manufactured by 

 Mr. J. Trotter, optician, Glasgow, and the price at which 

 1I1 \ are sold is 2s. 6d. 



We have received from Messrs. Isenthal and Co. their 

 latest publication on Moscicki condensers, and Giles valves 

 as applied to the protection of electric power transmission 

 lines against atmospheric disturbances and surges. High- 

 t ensiim condensers for radio-telegraphy in particular are 

 also dealt with. The publication is exceedingly well pro- 

 duced, the theory of surges and the practice of line and 

 station protection being dealt with in part i., while part ii. 

 deals chiefly with condenser batteries and choking coils and 

 radio-telegraphy. A summary of the contents of various 

 standard books dealing with these subjects is briefly given 

 and set nut with remarkable clearness in the brief descrip- 

 tion given. A noteworthy chapter is that dealing- with the 

 selection and design of plant, including generators, motors, 

 transformers, and switches, and some very useful tables are 

 included, giving safety coefficients for cables. The 

 pamphlet is well illustrated with photographs and diagrams 

 of the apparatus described. The Moscicki condensers and 

 Giles valves are once again very fully dealt with, togethei 

 with a list of places where they have been installed. 



Messrs. Watson's price list of apparatus for electro- 

 therapy and diagnosis is too well-known to require detailed 

 description. The novelties are principally found in the 

 therapeutic section. The " Prana " carbon dioxide snow 

 apparatus is described and illustrated. It is intended for 

 the treatment of nrevi and lupus, warts, and other super- 

 ficial diseases. The apparatus is made in three different 

 sizes. The carbon dioxide is contained in a cylinder, and 

 is allowed to escape into a receptacle which permits of free 

 evaporation with the production of carbon dioxide snow in 

 the form of a crayon 5 inches long by 1 inch or J inch in 

 diameter. A special high-frequency apparatus is con- 

 structed for diathermy or thermo-penetration. In this 

 apparatus the heating effect of the high-frequency current 

 is encouraged and used. Considerable benefit appears to 

 have been obtained in various rheumatic conditions and 

 neuralgia, sciatica, &c. These new high-frequency currents 

 an- at a voltage less than 3000 volts, but currents of 500 

 to 3000 milliamperes are used, and with the strongest doses 

 the patient feels absolutely nothing except the increase in 

 temperature. Thermometers introduced in animals prove 

 that the increase is internal, and greatest in the path 

 between the electrodes. Beyond the effects produced by the 

 heat there are no other physiological or chemical effects. 

 When the current is employed long enough, albumin 

 coagulates; and tumours, &c, can be destroyed by these 

 means : coagulated tissues behave like foreign bodies, and 

 are gradually expelled. In the radio-active substances 

 meso-thorium, of the same activity as pure radium bromide, 

 is quoted for at the price of 12/. iox. per milligram. 

 Radio-thorium is listed at the price of 1/. per gramme 

 Several special radium applicators are illustrated. 



Engineering for July 14 contains an illustrated di scription 



of a "Stock" oil-fired converter which is in opei iti 1 thi 



works di the Darlington Forge Co., Ltd. All classes ol teel 

 can be manufactured in this converter, from soft-steel cast- 

 ings to special steels of the highest class. In form it re- 

 nililes the ordinary Bessemer converter; it is lined with 

 ii\ silica lire brick, and is used, not only for thi 

 ision or blowing of iron, but also for melting the 11 tual 

 charge of iron and scrap by means of oil fuel, no separate 

 a 1" ing required. The oil fuel — crude petroleum — is 

 NO. 2177, VOL. 87] 



used for melting the < harge, and when this has been 

 effected the oil pipes an withdrawn and blowing com- 

 mences. The air doi 5 not - titer at the bottom and pass up 

 through the molten metal as in a Bessemer converter, but 

 is blown down on the top of the metal. For a three-ton 

 converter, melting takes about U, hours and blowing from 

 fifteen to twenty minutes, the total time, including charge, 

 being about two hours. As an example of the punishment 

 the steel will stand, the following may be mentioned : A 

 steel wheel, about .) leei o inches iii diameter, was dropped 

 edgewise on a steel ingot from the following heights — 5 

 feet, 10 feet, 15 feet, and 20 feet, without showing signs of 

 fracture. A drop of 40 feet on the rim broke one spoke. 

 After this four more drops of 40 feet on edge caused no 

 further fracture either to the rim or the spokes, and the 

 wheel was finally broken up by a steel three-ton ball 

 dropped ten times on the boss from a height of 40 feet. 

 Some remarkably thin castings have been made. 



OUR ASTRONOMICAL COLUMN. 



Comet, 1911b. — Observations of the new comet discovered 

 at the Lick Observatory on July 6 are recorded in No. 4511 

 of the Astronomischc Nachrichten. Prof. Abetti, at Arcetri, 

 on July 8, estimated the magnitude as 6'o, and Prof. Wolf 

 found, the same day, that the photographic magnitude was 

 7"5 ; his photographs show a tail. 



MM. Lagrula and Schaumasse observed the comet at Nice 

 on July 8, and, in Xo. 2 of the Comptes rendus (July 10), 

 they describe it as a bright object presenting a globular 

 condensation surrounded by a nebulosity which is extended 

 towards the S.S.W. ; the whole appears to have a diameter 

 of about 2'5'. 



From observations made on July 6, 8, and o. Prof. Kobold 

 has determined the following elements, which are said to 

 be similar to those of Comet 1790 I. 



Elements. 

 J =1911 June 20-6354 (M.T. Berlin) 

 <" = 99° '3t'99"| 



a = 172' 27-52' J-19110 



i =148° 39-25' J 

 log q =9-89956. 



An ephemeris derived from these elements gives 4I1. 26m. 

 27s., +32 54'o' as the position for July 20 (i2h. Berlin 

 \l. I '.), with a daily decrement of about 2m. in R.A. and 

 13' in declination. The calculated magnitudes for July 12 

 and July 20 are 6'j and 6\} respectively. Given a clear 

 horizon the object should be visible, with opera-glasses, 

 from midnight to dawn : at about [O.30 it rises some 30 

 east of north, and at 2 a.m. is about 20° above the horizon. 

 The present position is about one-third the distance betwei 1 

 1 Aurig;c and c* Persei from the former star along a straight 

 line joining the two. 



The Solar Eclipse of April 2S, 1011. — Dr. L. A. Bauet 

 sends us a detailed narrative of a journey to Tau Island 

 of the Manua group, where observations were made of the 

 total solai eclipse of Vpril 28, inn. The U.S. cruiser 

 innapolis took Dr. Bauer from Pago-pago harbour, Tutiula 

 Uland, to Tau. Dr. Bauer's prime object was to secure 

 magnetii Observations during the eclipse, and he arranged 



for simiilljn 110 ns to be made at the five 



magnetic observatories of the U.S. Coast and Geodetic 

 Survey, as well as at \pia, Christchurch, and Melbourne. 

 Ilis attention was, therefore, devoted to this subject, and 

 the astronomical ob vere made by officers of the 



ship. 



Mr. Vbbot, d hi Vstrophysical Observatory of 



the Smithsonian Institution, provided Dr. Bauer, at short 

 notice, with a hand quatorially mounted, double- 



lens cainr ra ol ibou focus, ested one 



exposure of 15s., and another as long about 



mi, ios. Thi made, and foui nega 



were obtained as the result. On account of a difficulty 

 with the sighting 1 befon totality, a hastily- 



constructed findei had t< be employed, and this did not 

 prove whollj -1 means of keeping the image 



