136 CARNEGIE INSTITUTION OF WASHINGTON. 



temperature measurements). It is also shown that values of the latent 

 heats differing from these by as little as 10 per cent will not give a like result. 

 This extreme agreement with the requirements of theory and its bearing on 

 certain theoretical questions is discussed. 



The geological significance of the complete solid solution of the feldspars 

 is considered, as well as the extent to which zoning may occur under favor- 

 able conditions and the consequent very great range of temperature through 

 which plagioclase may crystallize. 



(13) Die Schmelzerscheinungen bei den Plagioklas-Feldspaten. N. L. Bowen. Z. 



anorg. Chem., 82, 283-307. 1913. 



A German translation of "The melting phenomena of the plagioclase 

 feldspars" (Am. Jour. Sci. (4), 35, 577-599, 1913). Reviewed under No. 

 12 above. 



(14) New modified thermo-electric methods in calorimetry. Walter P. White. J. Wash. 



Acad. Sci., 3, 319-321. 1913. 



In the common calorimetric method, the "method of mixtures," the 

 work of the last five years has shown that the error due to heat-loss from 

 the calorimeter into the air, once thought to be an unconquerable foe to 

 accuracy, is ordinarily quite negligible. With a proper installation, the 

 attainment of very high precision, to 0.1 per mille or better, requires merely 

 sufficient precision in the temperature measurement. Such precision has 

 been attained with the thermo-electric thermometer system, as has already 

 been shown elsewhere. The present paper deals with the securing of cer- 

 tainty and high precision by means of the thermo-element. The essential 

 feature of the methods is to use, around the "cold junction" of the thermo- 

 element, in place of an ice-bath, a body at nearly the same temperature as 

 the calorimeter. The smallness of the electrical quantity to be measured 

 then gives to the temperature measurement extraordinary precision com- 

 bined with extraordinary ease. These methods, accordingly, while specially 

 advantageous for precision in determining very small heat quantities, are in 

 nearly all cases among the best in convenience and certainty. A precision 

 of 0.0001° is easily reached, under fair conditions, with a thermo-element 

 of 24 couples. Elements of 8 couples, ordinarily precise to 0.0003°, are so 

 very compact that the use of anything smaller will rarely be advisable. 



(15) Note on the temperature in the deep boring at Findlay, Ohio. John Johnston. 



Am. Jour. Sci. (4), 36, 131-134. 1913. 



A record of a series of temperature observations made in a hole drilled to 

 a depth of 3,000 feet in the neighborhood of Findlay. The temperature 

 gradient in the sedimentary rocks at horizons between 1,100 and 2,600 feet 

 proved to be about 0.41° C. per 100 feet, which is smaller than what has been 

 considered the common average value of this gradient. 



(16) Data on the intrusion temperature of the Palisade diabase. R. B. Sosman and H. 



E. Merwin. J. Wash. Acad. Sci., 3, 389-395. 1913. 



In the Palisade diabaseof New York and New Jersey there frequently occur 

 slabs of shale and arkose sandstone which seem to have been floated up into 

 the diabase sheet while the latter was still liquid. A study was made of the 

 comparative fusing temperatures of the diabase and the arkose. The lowest 

 melting portion of the diabase begins to fuse at about 1150°, but only at 

 1225° is enough of the rock fused to permit it to flow readily. The arkose 



