470 



NATURE 



[March 17, 1898 



attached scale, when that form of thermometer is used. Oppor- 

 tunity for the determination of the amount of this error has 

 offered itself at the Physikalisch-Technischen Reichsanstalt. 

 Two pairs of thermometers, each pair being made of similar 

 glass, and one pair divided on the stem, and the other on the 

 scale, have been rigorously tested. The result is that the third 

 place of decimals is not trustworthy if precautions have not been 

 taken to remove the effects of the expansion of the scale. The 

 other has reference to the accuracy of thermometric readings 

 when the instrument is exposed in a medium whose temperature 

 is rapidly changing. Dr. Hergesell, of Strassburg, in his in- 

 vestigation of the temperature of the air at considerable eleva- 

 tions, as derived from heat- registering apparatus carried in 

 balloons, has been led to the conclusion that in order to ascertain 

 the temperature of the air, it is necessary to take into account 

 two corrections which can have a very important effect upon 

 the result. One of these corrections, depending upon the 

 velocity with which the registering apparatus is carried through 

 the air, he has endeavoured to determine by actual experiment 

 made in the Seewarte at Hamburg. The thermograph was 

 mounted upon the whirling apparatus used for testing the ane- 

 mometers, and driven with various degrees of velocity varying 

 from zero to seven metres per second. The thermograph was 

 warmed to about 30° C, and precautions taken to ensure 

 uniformity in the distribution of the temperature. The arms 

 were then rotated, and when the temperature of the thermo- 

 graph had fallen to that of the testing-room, the resulting 

 curves show the rate of cooling under the varying velocities. 



The second correction, which Dr. Hergesell calls the 

 "inertia coefficient" in the paper referred to above, depending 

 upon the variation of density of the^surrounding medium, cannot 

 be determined experimentally with the same ease. The author 

 prefers to use the temperature recorded on the thermogram at 

 equal, but considerable, altitudes on the ascending and descend- 

 ing journey. At an altitude above 4000 m. it may be assumed 

 that the daily variation of temperature ceases, and therefore the 

 difference of time at which the two readings are taken is im- 

 material. Dr. Hergesell makes use of the record of the balloon 

 journey made February 18, 1897, from Paris. The temperature 

 records in ascending and descending are arranged as functions of 

 the atmospheric pressure, and show on the whole a tendency to 

 regular deviation from each other. The greatest separation 

 occurs at a pressure of 400 to 500 mm , while at 200 mm. the 

 curves tend to become parallel. Dr. Hergesell assigns to the 

 "inertia coefficient," which at the usual atmospheric pressure 

 is unity, a value four times as great in a density corresponding 

 to a pressure of 500 mm. In thermographs as at present 

 arranged, the difference arising from these two sources of error, 

 between the reading indicated and the true temperature, may 

 amount to as much as 12°. 



The eleventh annual report of the Liverpool Marine Biology 

 Committee has lately appeared, containing an account of the 

 work done at the biological station at Port Erin during 1897. 

 The year has been comparatively uneventful, but among the 

 recent developments of the work of the station we notice a 

 scheme for the simultaneous observation and record of surface 

 organisms at different stations in the Irish Sea. Attention may 

 be called to an obvious error on p. 13, in regard to the specific 

 gravity of the sea-water in the tanks. 



Mr. H. L. Clark has described the development of a vivi- 

 parous Synapta which is abundant among algae attached to 

 mangrove roots in the West Indies. His observations induce 

 him to support Lud wig's views concerning the degraded rank 

 of the Synaptidae in opposition to Semon's interpretations. In 

 regard to the ancestry of Echinoderms as a whole, he again 

 opposes Semon, and finds himself in close agreement with Bury; 



NO. 1481, VOL, 57] 



but, as the development of Synapta vivipara is direct and with- 

 out metamorphosis, it is obvious that his criticisms of Semon's 

 work cannot be regarded as final. 



A RECENT number of the yournal of the Society of Arts con- 

 tains an excellent review of the late outbreaks of plague in 

 Bombay, by Mr. H. M. Birdwood. An account is given of the 

 organised endeavours of the Government to combat the scourge, 

 and some real idea of its extent may be gathered from the 

 statement that up to the end of last year 56,000 deaths from 

 plague had been reported for the whole Presidency, but that the 

 actual number was probably not less than 70,000. Opinion 

 appears to be unanimous that the utter disregard of the poorer 

 natives for the commonest sanitary laws, and the horrible houses 

 and " chaw Is " in which they principally live, are largely respons- 

 ible factors for the firm hold which the disease has taken in the 

 city of Bombay. The eminent authority. Dr. Cleghorn, who was 

 deputed by the Government of India to study the position of 

 affairs in Bombay, has vividly described the housing of the 

 native population there. He tells us that the so-called chawls 

 are mostly great buildings five to seven stories high on the flat 

 principle, each flat containing a long corridor with rooms about 

 8 feet by 12 feet in size opening into it on either side ; these 

 rooms were usually inhabited by six to eight or even more 

 persons, and the state of filth in these corridors, which are 

 practically the receptacle for refuse from all the rooms, is in- 

 describable. Each chawl contains from 500 to 1000 persons,, 

 and 70 per cent, of the native population are housed in this 

 way. Dr. Cleghorn further goes on to say that such places were 

 only to be seen in Bombay, and the marvel is not that so much 

 plague abounded, but that it had not carried away at least half 

 of the population. To cope with this terrible legacy of past 

 generations of responsible authorities is no light task, but the 

 Government are devoting their most earnest attention to carry- 

 ing out a large and important scheme for the sanitary renovation 

 of Bombay. It is discouraging in the highest degree to find 

 that, despite all the heroic efforts which have been made to cope 

 with the scourge, it has appeared with renewed strength, and 

 an epidemic has been established for a second season in 

 Bombay. 



We have received from the Director, Mr. N. A. F. Moos, the 

 Report of the Bombay Magnetic and Meteorological Observatory 

 for the year 1896. In addition to the general tables giving the 

 readings of the self-recording magnetic and meteorological in- 

 struments, the report contains an account of the absolute measure- 

 ments made during the year in order to standardise the self- 

 recording instruments. In an appendix a short account is given 

 of the disturbances produced on some of the self-recording instru- 

 ments by the earthquake on June 12, 1897. Enlarged copies of 

 the photographic trace of the disturbed instruments are included, 

 which add considerably to the interest of the report. From the 

 character of the disturbances the Director concludes that the 

 disturbance of the magnetic instruments was not entirely of a 

 mechanical nature, but that the earthquake did really produce a 

 disturbance of the magnetic elements. The appendix also con- 

 tains a discussion of fifty years' observations of declination made 

 with one of Grubb's declinometers at the observatory. 



The United States Weather Bureau has published a discussion 

 of the Floods of the Mississippi River, prepared by Mr. Park 

 Morrill, the Forecast Official in charge of River and Flood 

 Service. The paper refers to the chief characteristics of that 

 river and of the basin that is drained by it, and contains valu- 

 able and trustworthy information as to the rainfall (which is the 

 principal cause of the floods) and drainage under normal condi- 

 tions, by means of a large number of tables and charts. These 

 show that the difference in the amount of summer and winter 

 rainfall is very great, the former being five or six times the latter 



