534 



NATURE 



[September 25, 1890 



also previously made its appearance in an engineering publica- 

 tion, but the contribution of Mr. Vernon on this subject was 

 taken as read. 



On Saturday, the 8th inst., only three papers were taken. 

 Prof. A. Lupton read a contribution on the pneumatic distribu- 

 tion of power ; in the course of which he gave some interesting 

 details of the important system which is now working at Bir- 

 mingham. This paper gave rise to a good discussion, in the 

 course of which the author was sharply taken to task for the 

 efficiency he claimed for the system. It should be pointed out, 

 however, that Mr. Lupton did not speak of "efficiency" as 

 looked at from a scientific standpoint, but from a commercial 

 point of view, which enabled him to take credit for certain waste 

 heat, not obtained from the power installation, which would 

 otherwise be thrown away. This was plainly stated in the paper. 

 Mr. F. G. M. Stoney's paper on the construction of sluices for 

 rivers, &c., was next read. The subject was of course well 

 treated by the author, and the paper was acceptable ; but there 

 was little novel in it, except the reference to the new tilting 

 sluices which are to be put up in connection with the new lock 

 at Richmond. Mr. Cope Whitehouse's paper on the Raiyan 

 reservoir was listened to by a thin audience, the preparation for 

 the afternoon's excursions calling the majority away. 



Monday in Section G is now given over to applied electricity, 

 and there is invariably a large influx of the more abstract 

 A's into the section. The Leeds meeting was no excep- 

 tion to this rule, and when Sir William Thomson opened the 

 proceedings by reading his paper the People's Hall, which the 

 section occupied, had quite a crowded appearance. The subject 

 which first occupied Sir William's attention was the new electric 

 meter which he has recently brought out. This apparatus is yet 

 in the experimental stage. Perhaps Sir William will be able to 

 do something towards cheapening the design. An example of 

 the meter was shown in operation on the platform. In the dis- 

 cussion which followed, Prof. P'leming made some pertinent 

 remarks on the effect of rough and smooth surfaces. The multi- 

 cellular voltmeter and the engine-room voltmeter described by 

 the author had previously been brought before the public 

 through the medium of technical literature. A new form of 

 voltapile, also described, was an instrument which was intended 

 for standardizing operations. Mr. Gisbert Kapp described the 

 Linefif system of electric traction, by means of which a partially 

 buried conductor can be used with safety to man and beast. 

 Messrs. Lawrence and Harries next read a paper on alternate 

 V. continuous currents in relation to the human body. No 

 doubt at times the effect of electrical currents on the human body 

 possesses a very intense interest for engineers, nevertheless the 

 paper was hardly suitable for the Mechanical Section. It is 

 well, however, that engineers should remember, as was stated in 

 the paper, that not voltage only, but current strength is the 

 important factor in estimating the danger from accidental con- 

 tact. In the discussion which followed, the late American execu- 

 tion naturally occupied a prominent place. Mr. Wilson Hartnell 

 brought the meeting back to a more mechanical complexion by 

 reading a paper on electric lighting and fire insurance rules, 

 illustrating his remarks by practical examples. He succeeded 

 pretty conclusively in showing that the fire insurance companies 

 want instruction in electrical matters, and, we think, at the same 

 time, he surprised some of those present, who certainly have 

 had considerable experience in electrical matters, by the result 

 of his experiments. The paper was eminently practical and 

 worthy of study by engineers. The last paper on the list for the 

 •day was by Mr. W. J. S. Barber Starkeyon secondary batteries, 

 in which the author described his system of adding carbonate of 

 soda to secondary batteries. The subject is not new. 



Tuesday, the 9th inst., was the last day on which Section G 

 met. Mr. Preece first occupied about five minutes in reading a 

 short contribution on submarine cables for long distance tele- 

 phony. Mr. F. Higgins next exhibited the " Column Printing 

 Machine," after which Mr. Arthur Greenwood read his paper on 

 heavy lathes. Mr. W. Bayley Marshall followed with a sug- 

 gestive paper on factors of safety, in which he gave the results 

 of a large number of tests of iron and steel extending over a 

 period of five or six years. The conclusion he had come to was 

 that in roof and bridge work elastic limit, and not ultimate 

 tensile strength, should be the important factor, but in the dis- 

 cussion that followed, which was the best discussion during the 

 meeting, the pertinent question was raised as to what " elastic 

 limit " is. A paper by Mr. J. H. Wicksteed on the measure- 

 ment of elongation in test samples was also well discussed. A 



paper by Mr. A. Mallock, on the measurement of strains, in 

 which the author described an instrument he had devised for the 

 purpose, and an exhibition by Prof. Barr of a mechanism for 

 giving vertical motion to a camera,' brought the business of the 

 Section to a close. 



NO. 109 1, VOL. 42] 



SCIENTIFIC SERIALS. 



American Journal of Science, September. — Rocky mountain 

 protaxis .and the post-cretaceous mountain-making along its 

 course, by J. D. Dana. — The magneto-optical generation of 

 electricity, by Dr. Sheldon. It is well known that, by using 

 proper conditions, a beam of plane polarized light may be 

 rotated by an electromagnet, and that a reversal of the current 

 causes the plane to be rotated in the opposite direction. A 

 rapidly alternating current thus produces a rapid swinging to 

 and fro of the plane of light. The author has conducted the 

 converse experiment, and by oscillating the plane of polarization 

 through 90° about 300 times per second, has produced an 

 alternating current. — Contributions to mineralogy. No. 49, by 

 F. A. Genth, with crystallographic notes by S. L. Penfield. 

 The results are given of the examination of some specimens of 

 ferric sulphate from Mina de la Compania, Chili. — Chalcopyrite 

 crystals from the French Creek Iron Mines, St. Peter, Chester 

 County, Pa., by S. L. Penfield. — Koninckina and related 

 genera, by Dr. Charles E. Beecher. — The effect of pressure on 

 the electrical conductivity of liquids, by C. Barns. It is shown 

 that, both in the case of mercury and a concentrated solution ot 

 zinc sulphate, the effect of isothermal compression is a decrement 

 of resistance nearly proportional to pressure, and from this fact the 

 deduction is made that the immediate effect of rise of temperature 

 is a decrement of specific resistance. — Notice of two new iron 

 meteorites from Hamilton County, Texas, and Puquois, Chili, 

 by Edwin E. Howell. Analyses of the two meteorites are 

 given. — The Cretaceous of Manitoba, by J, B. Tyrrell. — On 

 mordenite, by Louis V. Pirsson. — Geology of Mon Louis Island, 

 Mobile Bay, by Daniel W. Langdon, Jun. — On Leptaenisca, a 

 new genus of Brachiopod from the Lower Helderberg group, by 

 Dr. Charles E. Beecher. — North American species of Stropha- 

 losia, by the same author. — Notes on the microscopic structure 

 of oolite, with analyses, by Erwin H. Barbour and Joseph 

 Torrey, jun. 



V Anthropologie, sous la direction de MM. Cartailhac,Hamy, 

 et Topinard, tome i., Nos. 3 and 4 (Paris, 1890). — The exotic 

 races at the Exhibition in Paris, 1889, by MM. Deniker and 

 Laloy. In this report the authors give the general results of the 

 anthropometric determinations they obtained from their examina- 

 tion of 145 individuals belonging to the most different races, 

 some of which had not previously been made the subject of 

 scientific inquiry. The value of their remarks on the various 

 Senegalese and other South African negroes is enhanced by an 

 admirable series of portraits, copied from spirited photographs 

 by Prince Roland Bonaparte. From the observations of the 

 authors, it appears that the negroes of West Africa may be 

 divided into three or four groups, differing in physical characters. 

 In fact, crispness of the hair, and a more or less dark coloration 

 of the skin, seem to be the only characteristics common to all. 

 The negro races generally are tall, have flat noses, and are of a 

 dolichocephalous type, each group presenting, however, certain 

 features which distinguish them from the remainder. The tvvo 

 leading varieties are separated by tribes which are small in 

 stature, with a very hairy skin, and are of a marked brachy- 

 cephalic type. This intermediate group is spread across Africa 

 from the extreme east to the west, in about 2° S. and 3° N. of 

 the equator, and it is among these peoples that the true pygmy 

 tribes are found, which under the name of Akkas or Tiki-Tiki 

 of the Nile, Batus of the Congo, Akoas of the Ogowe, have 

 become known to us through Stanley and other recent explorers. 

 According to Emin Pasha, to whom we are indebted for the few 

 particulars that we know regarding their physical character, the 

 mean height of these so-called negrilloes is i'36m., and their 

 mean cephalic index 79 ; brachycephalism being a marked 

 character in all the pygmy tribes. Very complete tables are given 

 by the authors. — New explorations at Solutre, by M. A. Arcelin. 

 Paleontologists will welcome the report here given of the various 

 explorations that have been in progress at Solutre since these ini- 

 portant deposits were first made the subject of scientific inquiry 

 in 1866. The extent of the beds, which at some points are fully 



