GEOPHYSICAL LABORATORY. lOI 



(3) Die mineralischen Eisensulfide. Von E. T. Allen, J. L. Crenshaw, und John 



Johnston; mit kristallographischen Untersuchungen von Esper S. Larsen. 

 Z, anorg. Chem., 76, 201-273. 1912. 



A German translation of "The mineral sulphides of iron" (Am. Jour. Sci. 

 (4), 33, 169-236, 1912). Reviewed in Year Book No. 10 (1911), p. 104. 



(4) Beitrag zur Untersuchung der Portlandzementklinker. tJber die hypothetische 



Verbindung 8CaO.Al203.2Si02. Von G. A. Rankin; nebst optischen Unter- 

 suchungen von Fred. Eugene Wright. Z. anorg. Chem., 75, 63-66. 1912. 



In this paper, experimental evidence is offered that the hypothetical com- 

 pound 8CaO.Al203.2Si02 suggested by Janecke (Z. anorg. Chem., 73, 200, 

 191 1 ) has no independent existence, but consists in fact of a mixture of three 

 compounds, in accord with the previous publication from this laboratory 

 ("Preliminary report on the ternary system CaO-AlaOg-SiOa ; a study of the 

 constitution of Portland cement," J. Ind. Eng. Chem., 3, 1-43, 191 1). At 

 ordinary temperatures (below 1404°) the mixture is made up of 3CaO.Si02, 

 aCaO.SiOa, and 3CaO.Al203. Neither the composition 8CaO.Al203.2Si02 

 nor any other composition approximating to it shows any new phase which 

 is not described and identified in the previous paper on the ternary system, 

 lime-silica-alumina (reviewed in Year Book No. 10 (1911), p. 92). 



(5) The nitrogen thermometer scale from 300° to 630°, with a direct determination 



of the boiling-point of sulphur. Arthur L. Day and Robert B. Sosman. 

 J. Wash. Acad. Sci., 2, 167-176. 1912. 



A preliminary publication of results contained in the following paper: 



(6) The nitrogen thermometer scale from 300° to 630°, with a direct determination 



of tlie boiling-point of sulphur. Arthur L. Day and Robert B. Sosman. 

 Am. Jour. Sci. (4), 33, 517-533- 1912. 



In the publication of the authors' investigation upon the absolute measure- 

 ment of high temperatures ("High temperature gas thermometry," Publica- 

 tion of the Carnegie Institution of Washington No. 157, 191 1), the follow- 

 ing paragraph occurs (p. 125) : 



"The chief source of present uncertainty [in high temperature gas-ther- 

 mometer measurements] is the temperature distribution over the surface of 

 the bulb in an air-bath. It would be possible to eliminate this error in the 

 lower portion of the scale by substituting a liquid-bath which could be stirred. 

 In fact, this was done for temperatures below 500° in the earlier work of 

 Holborn and Day, but has not, so far, been tried in the present investigation 

 because of the relatively secondary importance of the lower temperatures 

 to the ultimate purpose of the investigation (the study of silicates). For the 

 higher temperatures, no satisfactory liquid-bath has been found." 



The lower temperatures upon this scale, determined in an air-bath, come 

 out about 1° lower than the corresponding temperatures of the Reichsanstalt 

 scale (determined in a liquid-bath). 



In certain studies now under way in this laboratory on the effect of pres- 

 sure upon equilibria, greater accuracy is now required in the measurement 

 of these particular temperatures than had previously been necessary. We 

 therefore determined to repeat these measurements (up to 650°), with more 

 elaborate precautions to secure a uniform temperature about the bulb, this 

 being, as stated above, the one factor in our measurements about which some 

 uncertainty remained. The results are contained in the following table : 



