1919] METEOROLOGY. 15 



of the autoclave temperature, size of can, viscosity of the food, etc., such as are 

 encountered by the commercial canner. 



The apparatus consists of a constant thermojunction, which is maintained at 

 the temperature of the autoclave and is located just outside the can. The actual 

 temperature of this junction is obtained from the readings of a thermograph, 

 the bulb of which is placed close to the constant junction. Connecting the 

 thermograph bulb with the recording clock is a capillary tube which is led out 

 of the autoclave through a suitable steam-tight joint. Connected with the con- 

 stant junction is a series of variable junctions located in different parts of the 

 cells and joined through a cable of wires to a galvanometer outside of the auto- 

 clave, which records all differences in temperature. The apparatus, which is 

 illustrated diagrammatically and described in detail, is said to give very satis- 

 factory results. 



The bacteriology of canning' (Kansas Sta. Rpt. 1918, p. JfO). — An investiga- 

 tion of methods of canning vegetables is reported, the results of which indicate 

 that blanching does not aid in the sterilizing process, proper sealing aids greatly 

 in preventing spoilage of canned foods, salt, except in amounts too large to be 

 allowable, is of little value, and small amounts of acetic acid (vinegar) are of 

 value in preserving canned vegetables. 



Saving raisins by sulphuring, F. T. Bioletti and A. E. Way (California 

 Sta. Circ. 211 (1919), pp. 4> flff^- ^)- — This circular describes a sulphuring hood 

 to be used in sulphuring raisins as soon as they are stacked after rain. The 

 hood, consisting of a wooden frame covered with building paper, when made 

 from the specifications given will cover about 26 trays in two stacks and is said 

 to be easily handled by two men. A pan containing about 0.5 lb. of sulphur is 

 placed on the ground between the two stacks. After igniting the sulphur, the 

 hood is placed over the stacks and a little soil is shoveled around the base to 

 make it air-tight. The time during which the grapes must be subjected to the 

 fumes of sulphur dioxid has not been determined, but is thought to be between 

 5 and 35 minutes. 



It is said that by the use of this method the cost of stacking is much reduced, 

 and that even in the wettest and most unfavorable season the crops are not lost. 



Potato drying, J. Rutishauser (Die Kartoffeltrocknung. Bern, Switzerland: 

 Ferd. iri/ss, 1918, pp. 51). — A brief description is given of the potato-drying 

 industry in Germany, and suggestions are made for the establishment of such 

 industries in Switzerland. 



METEOROLOGY. 



Introductory mateorology, W. J. Humphreys et al. (Neiv Haven: Tale 

 JJniv. Press, 1918, pp. XII +150, pis. 19, figs. 50; rev. in Nature [London], lOS 

 (1919), No. 2581, pp. 123, 12Jf). — This book was prepared and issued under the 

 auspices of the Division of Geology and Geography, National Research Council, 

 for use in " the course of study outlined by the Committee on Education and 

 Special Training of the War Department for Students' Army Training Units." 

 The plan " involves an intensive study of the elements of the subject," but " the 

 book is not intended to be elementary in the sense that it needs no study on 

 the part of students or elaboration and explanation by the instructor." 



The relation between evaporation and the area of the evaporating surface, 

 W. Gallenkamp (Met. Ztschr. [Brunswick], 36 (1919), No. 1-2, pp. 16-22, fig. 

 1 ) . — Observations are recorded which show that in all cases the rate of evapora- 

 tion decreased with an increase in the extent of the evaporating area. The 

 decrease in evaijoration, however, was not directly proportional to the increase 



