February 9, 1893] 



NATURE 



157 



The revolving plate is kept in motion by clockwork, which is 

 set in motion by an electric seismoscope. (See No. 8.) 



2. Seismograph writing on a drum. — In this instrument the 

 record is written on a band of paper, the diagram being less 

 difficult to interpret because it is written to the right and left of 

 a straight line and not round a circle. 



3. Seismograph tvriting on a band of paper. — In this instru- 

 ment not only is the diagram written along a straight line but 

 it is written with pencil, — the trouble of handling smoked paper 

 being therefore avoided. When the earthquake ceases, the drum 

 ceases to revolve, but if a second or third earthquake should 

 occur, it is again set in motion. By this means a series of 

 earthquakes may be recorded, the resetting of the instrument 

 being automaiic. 



4. Seismograph without multiplying levers. — This instrument 

 is intended to record large motions, the horizontal levers not 

 being prolonged beyond the steady points to multiply the motion. 

 For large earthquakes, when the ground is thrown into wave- 

 like undulations, special instruments which measure tilting are 

 employed. 



5- Duplex pendulum seismograph. — In this case a steady 

 point is obtained by controlling the motion of an ordinary 

 pendulum with an inverted pendulum. The record consists of 

 a series of superimposed curves written on a smoked glass plate. 



6. Mantelpiece seismometer. — This is intended for the use of 

 those who simply wish to know the direction and extent of 

 motion as recorded at their own house. It is a form of duplex 

 pendulum, and it gives absolute measurements for small dis- 

 placements. 



7. Tromometer. — This is one form of an instrument which is 

 used to record movements which are common to all countries, 

 called earth tremors. Every five minutes, by clockwork contacts 

 and an induction coil, sparks are discharged from the end of the 

 long pointer to perforate the bands of paper which are slowly 

 moving across the brass table. If the pointer is at rest, then a 

 series of holes are made following each other in a straight line, 

 but if it is moving, the bands of paper are perforated in all 

 directions round what would be the normal line of perforations. 



The earth movements which cause these disturbances are 

 apparently long surface undulations of the earth's crust, in form 

 not unlike the swell upon the ocean. 



A more satisfactory method of recording these motions, which 

 has been used for the last two years, is by a continuous photo- 

 graph of a ray of light reflected from a small mirror attached to 

 a small but extremely light horizontal pendulum. 



8. Electrical contact maker. — These instruments are delicate 

 seismoscopes, which on the slightest disturbance close an 

 electric circuit, which, actuating electric magnets, set free the 

 machinery driving the recording surfaces on which diagrams 

 are written. 



9. Clock. — At the time of an earthquake the dial of this clock 

 moves quickly back and forth and receives on its surface three 

 dots from the inkpads on its fingers. It thus records hours, 

 minutes, and seconds, without being stopped. 



10. Model of an earthquake. — The bent wires represent the 

 path traced by an earth particle at the time of the earthquake of 

 January 15, 1887. The numbers indicate successive seconds. 

 This model was made by Prof. S. Sekiya. 



11. Safety lamps.— These are lamps which if overturned are 

 at once extinguished. One of these is a European invention 

 and the other Japanese. 



12. Pictures. — The pictures on the walls show the effects of 

 the Great Earthquake of October 28, 1891, the devastation 

 followmg the Eruption of Bandaisan in 1887, and several of the 

 more important volcanoes in Japan. Thev were made by Prof. 

 W. k. Burton. John Milnk, F. Omoki. 



beismological Laboratory, Imperial University of Japan, 

 Tokio. 



UNIVERSITY AND EDUCATIONAL 



INTELLIGENCE. 



Oxford.— Last Term the Board of Faculty of Natural 



bcience recommended that an honour examination in Natural 



bcience should be instituted, bearing the same relation to the 



l-inal School that Moderations bear to the Final School of 



Literae Humaniores. The recommendation of the Board was 



not unanmious, and on the matter coming before the Hebdo- 



madal Council last week, it was ])ut aside on the ground of want 



NO. I 2 15, VOL. 47] 



of unanimity among the various scientific departments. There 

 was much to be said both for and against the proposed examina- 

 tion. It would probably have raised the standard of the 

 chemical and physical work done by biologists, but would have 

 forced an additional subject on the chemists and physicists, 

 which they were very unwilling to assent to. 



Cambridge. — The Adams Prize has been awarded to Prof. 

 J. H. Poynting, F.R.S., late Fellow of Trinity College, for a 

 memoir on the methods of determining the absolute and 

 relative value of gravitation and the mean density of the earth. 



The Professor of Pathology (Mr. Roy) gives notice that on 

 Thursday, February 9, a lecture and demonstration will be given 

 by Dr. Hafkine, of the Pasteur Institute, on his method of 

 conferring immunity against Asiatic cholera. The lecture will 

 be delivered at the Pathological Laboratory at 4.30, and will be 

 open to members of the University. 



The office of Esquire Bedell has been rendered vacant by the 

 death of Mr. F. C. Wace, a distinguished mathematician, 

 formerly Fellow and Lecturer in Mathematics at St. John's 

 College, and thrice elected Mayor of the Borough of Cambridge. 



SCIENTIFIC SERIALS. 



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

 Essay towards an extension of Maxwell's Theory, by Hermann 

 Ebert. The author obtains expressions for dispersion and 

 absorption of waves of the order of light-waves analogous to 

 those obtained by Goldhammer, and shows that they may be 

 derived from Maxwell's fundamental conceptions by applying 

 them to the case of rapidly changing displacements. — A new 

 kind of magnetic and electric measuring apparatus, by G. 

 Quincke. These are made of glass, ebonite, and wood. No 

 screws are used in their construction, and they are claimed to 

 cost a tenth of the price of ordinary instruments, with equal 

 accuracy. In each of them the needles are suspended at the 

 hollow centre of a vertical circular glass disc. — On a null 

 method for measuring the dielectric constants of conducting 

 liquids, by Friedrich Heerwagen.— On a phenomenon analogous 

 to Newton's rings observed during the i assage of Hertz electric 

 plane waves through plane-parallel raetal plates, by Ludwig 

 Boltzmann. The author removes an apparent contradiction 

 between Maxwell's theory and Hertz's observation that even 

 excessively thin metal plates do not transmit electric waves a 

 few decimetres long, by showing that this is not due to absorp- 

 tion, but to the limiting conditions at the surfaces of separation 

 deducible from Maxwell's formulae. — On a medium whose 

 mechanical properties lead to the equations propounded 

 by Maxwell for electromagnetism, by L. Boltzmann. — On 

 some questions concerning Maxwell's theory of electricity, by L. 

 Boltzmann. — The index of refraction of electric rays in alcohol, 

 by H. O. G. Ellinger. — On the electrification of air in glow 

 and brush discharges, by Ad. Heydweiler. — On the calculation 

 of magneto optic phenomena, by P. Drude. — Spectra of 

 aluminium, indium, and thallium, by H. Kayserand C. Runge. 

 — On the infra-red spectra of the alkalies, by H. Kayser and 

 C. Runge. A criticism of Benjamin Snow's work on the same 

 subject. — Investigations concerning interior conduction of heat, 

 by Richard Wachsmuth. — On the absolute value of the thermal 

 conductivity of air, by A. Winkelmann. — On a modification of 

 the transpiration method suitable for the investigation of very 

 viscous liquids, by C. Brocfmann. The substance was made to 

 pass from a funnel-shaped reservoir through a capillary tube 

 into a beaker standing on one pan of a chemical balance. The 

 time was noted at which the amount of liquid passed into the 

 beaker v/as large enough to overcome the counterpoise in the other 

 pan, and to disturb the equilibrium, and further small weights 

 were added and similarly dealt with. The temperature was 

 kept constant by a spiral water-pipe and felt jacket, and local 

 differences and variations of level and buoyancy were corrected 

 for. The liquid experimented upon was glycerine, and the 

 temperature curves were hyperbolas. — Notes on M. Cantor's 

 thesis on capillary constants, by Th. Lohnstein. — Note on the 

 purification of mercury, by W. Jaeger. 



Notes from the I.eyden Museum. — Of volume xiv. numbers 

 I and 2 were published in April, and numbers 3 and 4 in July 

 last. Edited by Dr. F. A. Jentink, this volume contains 282 

 pages and ten plates. The notes on Mammals are ; by the editor 

 on Semnopithecus pyrrhus, Horsfield ; and on Pithecir melan- 

 urus, S. Muller (Pis. 3 and 4). In volume, xii. Dr. Jentink, 



