January 10, 1908] 



SCIENCE 



75 



menta for the meeting most successfully. We 

 were given free use of the excellent social club 

 at the Hague: the Minister of Colonies gave 

 a dinner and a reception, and an excursion 

 was made by boat through the canals; alto- 

 gether the visit to the Hague was extremely 

 agreeable and its memory will always be a 

 pleasure. 



According to the by-laws only the delegates 

 are admitted to the meetings of the permanent 

 commission, but this rule has never been en- 

 forced, so that all persons attending the gen- 

 eral assembly also attended the meeting of 

 the permanent commission. The general as- 

 sembly has not a permanent president, but the 

 chair is occupied in rotation by different mem- 

 bers. The permanent commission elects its 

 president for four years. Signer Palazzo, of 

 Italy, was the retiring president; and Pro- 

 fessor A. Schuster, of Manchester, England, 

 was elected president for the next four years. 

 Professor Forel, of Switzerland, was elected 

 vice-president for two years; and the next 

 meeting of the permanent commission was 

 fixed to take place in Switzerland two years 

 hence; Strassburg was continued as the cen- 

 tral bureau of the association for the next 

 four years. 



The report of the central bureau showed 

 that it had made careful studies of seismolog- 

 ical instruments at Strassburg during the last 

 year and that it had published the catalogue 

 of earthquakes for the year 1904. This list 

 is arranged chronologically, but it was sug- 

 gested that future lists, which are to be made 

 by the central bureau, should have a different 

 arrangement, namely, that the earthquakes 

 should be grouped regionally. The details of 

 the publication of the new catalogues were put 

 in the hands of a sub-committee. The central 

 bureau has also published all the seismograms 

 of the Valparaiso earthquake, or at least all 

 of which it could obtain the originals. These 

 have been reproduced by a heliograph process 

 so as to be exact, and comprise 140 plates, 

 32 by 42 em. each. This will furnish an 

 opportunity for a careful comparison of the 

 seismogramis of one great world-shaking 

 earthquake. 



At the Rome meeting of the permanent 

 commission in October, 1906, a prize was of- 

 fered for the best cheap seismograph, the 

 details of the competition being left to the 

 central bureau. The conditions imposed were 

 that the instruments should not cost more 

 than about 300 Marks, that it should record 

 one component of the movement and should 

 magnify from 40 to 50 times. The results 

 were not very satisfactory. The low limit of 

 the price seems to have kept out some com- 

 petitors, so that only four competing instru- 

 ments were exhibited at the Hague. One of 

 these, shown by Professor Agamennone, con- 

 sisted of two horizontal pendulums at right 

 angles to each other and supported by pivots; 

 between them was a horizontal pendulum ar- 

 ranged to record the vertical motion. All 

 three instruments recorded on smoked paper 

 and on a single drum. The price of this 

 instrument was 550 Marks ; but in view of the 

 fact that all three components were registered, 

 it was admitted to the competition. Spindler 

 and Hoyer, mechanics of Gottingen, exhibited 

 an inverted pendulum of the Wiechert type 

 weighing about 80 kilograms, which recorded 

 the two horizontal components on a single 

 drum, and magnified from 40 to 120 times. 

 The price of the instrument was 350 Marks. 

 The same mechanics also exhibited a pendu- 

 lum for vertical movement which had a grid- 

 iron arrangement to prevent shifting of the 

 instrument by changes of temperature. This 

 instrument cost 550 Marks and was accord- 

 ingly excluded. The third instrument, made 

 by Schmidt, of Utrecht, Holland, was a small 

 inverted pendulum recording the two hori- 

 zontal components on a single drum; the 

 whole instrument did not occupy more space 

 than about one cubic foot and its magnifying 

 power was about 200. These instruments are 

 to be sent to Strassburg and their relative 

 efliciency carefully tested before the prize is 

 awarded. 



It has been the tendency of the association 

 to refer all investigations to the central bu- 

 reau. There was a reaction against this at 

 the Hague meeting, and the new investigations 

 ordered were put into the hands of special 



