1920J METEOROLOGY. 809 



A practical study of corncob utilization, F. B. La Forge {Chem. Age [New 

 York], 28 (l'J2U), No. 9, pp. 332S36, fig. i).— The author discusses the possi- 

 hilities in the commercial utilizatiou of corncobs on the basis of chemical 

 studies conducted at the Bureau of Chemistry, U. S. Department of Agricul- 

 ture, a report of which by La Forge and Hudson has been previously noted 

 < E. S. K., 4U, p. 17). It is thought that lUU tons of cobs can be made to yield 

 about 45 tons of adhesive "A," 30 tons of adhesive "B," 35 tons of cellulose, 3 

 tons of acetate of lime, and li tons of furfural. Adhesive "A " is a thick 

 brown solution of gums which is obtained by heating the dry cobs with 

 water under pressure and concentrating the resulting extract. Adhesive "B " 

 is obtained by grinding the press-cake resulting from the extraction of ad- 

 hesive "A" and boiling it with 1 per cent sodium hydroxid solution to separate 

 the alkali-soluble material from the true cellulose. The resulting black liquid 

 is evaporated to proper consistency for adhesive uses. Adhesive "A" may, if 

 desired, be converted into furfural by heating it with dilute mineral acids. 



A brief description is included of the various steps in the proposed process, 

 together with estimated costs and returns of plants dealing with 100 and 

 with 50 tons of cobs daily. 



METEOROLOGY. 



Evidence of climatic eflfects in the annual rings of trees, A. E. Douglass 

 (Ecology, 1 (1920), No. 1, pp. 2^-82, 66, figs. 10).— The evidence here presented 

 " has emerged in the process of dating and measuring about 85,000 annual 

 rings which had grown in some 275 different trees in the States of Oregon, 

 California, Arizona, Colorado, and Vermont, as well as in England, Norway, 

 Sweden, Germany, and Bohemia." The evidence is of three kinds, (1) the 

 direct correlation between the annual rings of yellow pine (Pinus ponderosa) 

 and the rainfall at Prescott, Ariz.; (2) the marked resemblance found in cer- 

 tain individual rings over a wide extent of the country in which climate is the 

 only common factor; and (3) an extension of (2) which, however, instead of 

 merely taking into account similarities in individual rings, uses similarity 

 in ring variation over large areas as determined by a form of harmonic 

 analysis using an instrument devised by the author, called a periodograph, 

 capable of analyzing plotted curves into their component cycles, if such exist. 



It is found that " the rings of the yellow pine in northern Arizona show 

 varying thickness in marked correlation with rainfall; the sequoias of Cali- 

 fornia show similar characteristics in less degree. Climatic effects may also 

 be detected by similarity In ring-growth over large areas." The author con- 

 cludes that such studies may be made to disclose climatic combinations ad- 

 vantageous to certain types of vegetation, and may enable us to outline what 

 might be called agro-meteorological districts — that is, areas over which exist 

 similar advantageous combinations of weather elements. 



A characteristic called " mean sensitivity " is suggested as a possible meas- 

 ure of climatic reaction. " This may be described as the difference between each 

 two successive rings divided by their mean." The application of this criterion 

 " promises to make possible the proper selection of sequoia records, which, in 

 turn, will give us much climatic information about the last 3,200 years." 



Solar variation and the weather, C. G. Abbot (Nature [London], 105 (1920), 

 No. 2648, pp. 678-680, figs. 2). — Pyrhelionietric and spectrobolometric observa- 

 tions, especially at Washington, Mt. Wilson, Mt. Whitney, and at Calama, 

 Peru, showing solar variability and indicating a correlation between it and 

 the weather, are briefly reviewed. It is shown that solar changes produce 

 large and prolonged temperature effects. The successful use of the observations 



