200 



NATURE 



[April 14, 1910 



Similar instruments installed in two districts of Tokyo, 

 3-29 km. apart, one on high and hard ground, the other 

 on low and very soft ground, showed that the pulsations 

 at the two places differed not only in phase, but also in 

 their mode of grouping, while the mean period and ampli- 

 tude were nearly the same. 



Bulletin No. 405, issued in 1909 by the United States 

 Geological Survey, consists of a full account of the pro- 

 longed and exhaustive investigations carried out by Dr. 

 W. F. Hillebrand and Dr. W. T. Schaller upon the 

 chemical and physical properties of the remarkably interest- 

 ing series of mercuric minerals, viz. kleinite, montroydite, 

 terlinguaite, eglestonite, calomel, and native mercury, 

 occurring at Terlingua, Texas. Of these, all, save the last 

 two, are minerals which were first discovered and are as 

 yet known only at this locality. Montroydite, terlinguaite, 

 and eglestonite were first described by Prof. A. J. Moses; 

 he noticed yet another possibly new mineral, but had not 

 at his disposal sufficient material for its determination. 

 The outstanding mineral was subsequently studied by 

 Prof. Sachs, who gave it the name kleinite, and announced 

 it to be an oxychloride of mercury with the formula 

 Hg^CljOj. One of the most interesting results arising 

 from Dr. Hillebrand's analyses is to show that the mineral 

 has a more complex composition, and is, indeed, a unique 

 example among minerals of the mercury-ammonium group 

 of salts. The precise nature of the molecular constitution, 

 however, still remains uncertain, and it rs not known 

 what part is played by the small but varying amount of 

 water present ; the mineral may possibly be a mixture of 

 the chlorine compound NHg^Cl with other salts of mercury. 

 The horqogeneity above 130° and the heterogeneity below 

 that temperature, as revealed by the optical characters, 

 show that kleinite must have been formed at a relatively 

 high temperature. Careful tests failed to reveal the 

 presence of nitrogen in any of the remaining minerals, but 

 Dr. Hillebrand found that the formula for eglestonite 

 should be Hg^Cl^O, and not Hg.CljOj, as deduced by 

 Moses from McCord's analyses. Dr. Schaller's careful 

 goniometric examination 'confirmed the fundamental con- 

 stants and the symmetry already found by Prof. Sachs 

 for kleinite and by Prof. Moses for the other minerals, 

 but added enormously to the number of forms discovered. 

 Dr. Schaller, who is evidently a whole-hearted disciple of 

 Prof. Goldschmidt, based his discussion of the forms on 

 the harmonic law enunciated by that versatile crystallo- 

 grapher. 



The meteorological chart of the North Atlantic Ocean 

 for March, issued by the Deutsche Seewarte, contains an 

 account of the second attempt at utilising wireless tele- 

 grams for weather forecasts. The experiment was made 

 in August and September, 1909, and the district of observa- 

 tion was restricted to io°-30° W. longitude. The results 

 tend to show that, so far as Germany is concerned, it is 

 doubtful whether practical use can at present be made of 

 the telegrams. The Seewarte considers that further study 

 of the connection between the weather of any particular day 

 in Germany and the preceding distribution of pressure over 

 the ocean, and especially of the tracks taken by baro- 

 metric depressions, is primarily necessary, and that this 

 study can best be done by an examination of the daily 

 synoptic charts which have been published for many years 

 by the Seewarte and the Danish Meteorological Institute. 

 We believe that similar telegrams were forwarded to the 

 London Meteorological Office : the results, so far as this 

 country is concerned, will no doubt be given in the com- 

 mittee's next annual report. 



NO. 21 II, VOL. 83] 



Bulletin No. 36 of the University of Illinois consists 

 of a paper on the thermal conductivity of fire-clay at 

 high temperatures, by Messrs. J. K. Clement and W. L. 

 Egy. The fire-clay specimens are cylinders 40 cm. long, 

 12 cm. in diameter, with a hole through the centre 35 cm. 

 in diameter for the reception of a heating coil of nickel 

 wire wound on a porcelain tube. The cylinders are further 

 provided with two long holes 3 mm. in diameter parallel 

 to the axis and extending to the central plane. Through 

 these pass the platinum platinum-rhodium thermocouples, 

 by means of which the temperatures at two points of the 

 central plane are determined. The specimens are enclosed 

 in a fire-clay furnace, which has an internal diameter 

 slightly greater than the external diameter of the speci- 

 mens. The heating current is measured by means of a 

 Weston voltmeter and shunt, and the thermocouples 

 standardised by means of zinc, silver, or copper freezing 

 in a carbon crucible in a special furnace. The electro- 

 motive force of the couple is measured by potentio- 

 meter and galvanometer. Two samples gave constant 

 heat conductivities of 0-0026 and 00036, respectively, 

 between 300° C. and 800° C, one other increased from 

 00021 at 300° C. to .0-0023 ^t 700° C, while a fourth 

 increased from 0-0024 ^t 400° C. to 00026 at 800° C. 



An illustrated article on the Royal Liver building, Liver- 

 pool, appears in the Builder for .^pril 9. With the excep- 

 tion of the outer curtain walls, the building has been 

 constructed entirely in ferro-concrete on the Hennebique 

 system. Mr. W. Aubrey Thomas was the architect, and 

 Messrs. L. G. Mouchel and Partners prepared the details 

 of the ferro-concrete work. The building is 301 feet long i 

 by 177 feet 6 inches wide, these dimensions continuing up 

 to the main roof at a height of about 170 feet above street- 

 level. The domes surmounting the main towers are 295^ 

 feet above street-level, the extreme height from foundation- 1 

 level to the topmost point being 360 feet, about the same 

 as that of St. Paul's Cathedral. This huge building has 

 eleven storeys up to the main roof, and six storeys in each 

 main tower. From the structural point of view the build- 

 ing is essentially a monolith. Each floor was moulded at 

 the same time as the corresponding columns and beams, 

 so that the men engaged in setting up the framework of 

 the next storey had the advantage of a continuous floor 

 for the conduct of operations. The granite curtain walls 

 constituting the exterior sheathing of the building are 

 nowhere more than 14 inches thick, the weight being 

 taken at each storey by lintels forming part of the general 

 framework. 



The first of a series of illustrated articles on the con- 

 struction of aeroplanes appears in the Engineer for .April 8, 

 and deals with the Farman biplane. This machine has 

 the distinction of being the first to combine the rear planes 

 for steadying purposes with ailerons or fins for obtaining 

 lateral stability. Mr. Farman began his career in aviation 

 as pilot of a Voisin biplane, a machine which depends for 

 stability on its cellular construction. Farman drifted from 

 the cellular aeroplane, and adopted the system of manual 

 control which in various forms is now almost general. 

 In the new Farman machines the planes have a supporting 

 surface of 48 square metres. The older types have two 

 planes of the same length, whereas the new machines have 

 the lower plane shorter than the upper, the lengths being, 

 respectively, 23 feet and 36 feet. The width and the height 

 between the planes are equal, being each 6 feet 2f inches. 

 Both ash and poplar are used in the construction. Most 

 Farman biplanes are fitted with the rotary Gnome engine. 

 A feature of the article is the numerous clear drawings 

 of details given. 



