June 2, 1898] 



NATURE 



[09 



into the various kinds of glazes in use there, and as to whether 

 any substitutes can be found for those containing lead. Not 

 only will the work undertaken by these gentlemen have a humane 

 bearing and be of a scientific nature ; it will be helpful also to 

 the manufacturers. This is the first instance (says the British 

 Medical Journal) in which the British Government has called to 

 its aid expert help, not only to assist it in framing regulations 

 for the health of the workers, but also of helping on industries. 

 As the manufacturers are sure to co-operate heartily with those 

 to whom has been entrusted this important special inquiry, it is 

 to be hoped that results will be arrived at which will remove 

 from one of our prosperous and oldest industries the stain that 

 has so long lain upon it. 



Dr. Agamennonb, who has paid considerable attention to 

 the velocity of earthquake-waves, has recently published a 

 valuable paper on the mean surface-velocity of the pulsations 

 from the great Calcutta earthquake of last June 12 {Rend, della 

 R. Accad. del Lincei, vol. viii., 1898, pp. 265-271). Relying 

 on accounts which have already appeared in Nature, he 

 assumes the centre of disturbance to be in 25° N. lat. and 91° E. 

 long. At Calcutta, which is 400 km. from this point, the time 

 of occurrence was iih. 46m. a.m. (Greenwich mean time) 

 according to Mr. La Touche ; and iih. 7m. according to Mr. 

 Oldham. The earthquake was registered by seismographs and 

 magnetographs at nineteen observatories in Europe, the most 

 distant being Edinburgh, 7970 km. from the epicentre. Ex- 

 cluding the record on the Pare St. Maur magnetograms, which 

 differs considerably from the others, the mean surface-velocity 

 of the earliest vibrations was either 9 or 11 km. per second, 

 according to the time taken for Calcutta. These first rapid 

 vibrations lasted for about 23 minutes, and were succeeded 

 by large long-period oscillations, the mean surface-velocity of 

 which was either 2 "61 or 276 km. per second. At Rome, the 

 period of these oscillations was about 10 seconds, and their 

 maximum amplitude 12". Thus, as it crossed Italy, the com- 

 plete wave must have been 54 km. in length, and the height of 

 its crest about half a metre. 



Senor Antonio Blazquez communicates to the Boldino 

 of the Madrid Geographical Society a preliminary paper on a 

 fresh investigation as to the precise length of the Roman mile. 

 The question has been a constant source of difficulty in con- 

 nection with the determination of the sites of ancient cities, and 

 the tracing of former inhabitants of the peninsula, and a great 

 cleal of evidence is discussed which goes to show that the Roman 

 and the Arab miles were of the same length : 1672 metres. 

 The length formerly accepted was 1481 metres. The detailed 

 investigation is promised in a future paper. 



Dr. C. Dammann adds another to the already numerous 

 monographs on German rivers in a paper on the Wupper, 

 published in the Verhandlimgen des nattirhistorischen Vereins 

 der preusstschen Rheinlande. A careful study is made of the 

 geology and geomorphology of the river and its basin, and of 

 the rainfall and drainage. The fact that the basin of the Wupper 

 consists almost entirely of impermeable rocks, gives the sudden 

 variations in the volume of the stream some special features, 

 especially with regard to floods. Some idea of the rapidity of 

 these changes is given by the record of the rate of discharge on 

 three successive days : 527, 182*3, and 517 cubic metres per 

 second. 



In Darwin's geological observations on the volcanic islands 

 visited during the voyage of H.M.S. Beagk, reference is made 

 to a " volcanic bomb " found in the interior of Australia. The 

 specimen was composed of green obsidian, and was found on a 

 great sandy plain between the rivers Darling and Murray, at a 

 distance of several hundred miles from any known volcanic 

 NO. 1492, VOL. 58] 



region. Many similar specimens of obsidian "buttons" have 

 since been found in Australia, and the Proceedings of the Royal 

 Society of Tasmania (1897) contains two short descriptive papers 

 on their occurrence in Tasmania. How these singular objects 

 found their way to some of the localities in Tasmania, where 

 their occurrence in undisturbed quartz drift far away from any 

 known volcanic source has been reported, is unexplained. That 

 they are volcanic products is unquestionable ; and their spheroidal 

 or discoid form points to rotation while in a fluid state. It has 

 been suggested that the objects came from lunar volcanoes, but 

 it is highly improbable (even if they were ejected from the 

 moon) that they would reach our globe, and if they did they 

 could not penetrate the atmosphere. Mr. T. Stephens, the 

 author of one of the papers referred to, thinks the aborigines of 

 Australia are probably largely responsible for the distribution of 

 the obsidian buttons over the mud-plains of Victoria and Riverina, 

 but no such explanation can be given in reference to most of 

 the places where they have been found in Tasmania. In a paper 

 by Messrs. W. H. Twelvetrees and W. F. Petterd in the Pro- 

 ceedings mentioned above, the suggestion is made that the 

 objects are products of terrestrial volcanoes of an acid or sub- 

 acid type, formerly in eruption in the southern hemisphere. 

 The nearest known source of tertiary obsidian is New Zealand, 

 but whether the objects have been transported through th«; air 

 from that island, or from the Antarctic continent or elsewhere, 

 it is impossible at present to decide. 



We learn from the Meleorologische Zeitschrift for April that 

 Signor Bofiito, librarian of the Moncalieri Observatory, near 

 Turin, intends to publish a repertorium of Italian meteorology, 

 which, like the valuable repertorium of German meteorology 

 published by Dr. Hellmann in 1883, will contain a practically 

 complete bibliography of meteorological works written in the 

 Italian language. As the meteorological literature of Italy was 

 especially rich in the fifteenth and sixteenth centuries, the pub- 

 lication of the proposed work will be very welcome. Signor 

 Boffito will be glad to receive notice of any works published in 

 the Italian language in other countries. 



In the U.S. Monthly IVeather Review for February an 

 interesting account is given of the value of a searchlight for 

 making weather signals known in large cities or seaports at an 

 hour of the evening when it is too late to give warning by the 

 usual method. In the month of February 1895, the searchlight 

 for the unfortunate battleship Maine, then nearing completion, 

 was lent for temporary use at the Chicago office of the Weather 

 Bureau, and the experiments were conducted by the present 

 chief of the latter institution. From observers and other 

 persons it was ascertained that the signals were clearly seen at a 

 distance of twenty miles. At present the great cost of main- 

 taining the apparatus in operation would preclude its adoption, 

 but in the event of the expense being eventually reduced, the 

 author thinks it might be used by the Weather Bureau for 

 the purpose of immediately disseminating forecasts made from 

 the evening observations. 



The relative merits of the weather predictions issued daily by 

 the U.S. Weather Bureau for one or two days in advance, and 

 those published by "farmer's almanacs" a year or more in 

 advance, were lately made the subject of newspaper paragraphs 

 in America, and are commented upon by Prof. Cleveland Abbe 

 in the Monthly Weather Review. Of course, no true comparison 

 can be made between the results ; for while the predictions 

 made by the Weather Bureau are based upon actual observations 

 of atmospheric conditions, the popular weather prophets depend 

 chiefly upon inspiration and astrological combinations, though 

 some do go so far as compile from the records of past years a 

 table showing what sort of weather has prevailed most frequently 

 on the respective days of the year, and use this table for 



