678 



SCIENCE. 



[N. S. Vol. I. No. 25. 



of the breccia were slightljr eroded by wave 

 action during the deposition of the green 

 shale in the surrounding water, but the 

 leveling had not proceeded far when the 

 Devonian age came to a close ; the entire 

 region was depressed, and the Louisiana 

 liniestone (formerlj^ known as the Litho- 

 graphic limestone) , or basal member of the 

 Kinder hook Group, was laid down over the 

 breccia. It is usually a regularly bedded, 

 dark gray limestone, everj'where perfectly 

 conformable to the green shale, but over 

 the distributed area it is irregularly bedded 

 and sUghtly arched, but soon succeeded, by 

 thickening in the hollows and thinning over 

 the prominences, in leveling off the ancient 

 sea bottom. The Lower Carboniferous 

 strata are here locallj^ unconformable with 

 the Devonian. We have thus seen that the 

 thinning of the green shale over the area of 

 disturbance fixes the time of said disturb- 

 ance at the period between the deposition 

 of Nos. 1 and 2 or the shaley limestone and 

 the green shale. From a general resem- 

 blance between the shaley liniestone of this 

 region and portions of the Cedar valley 

 limestone of Iowa, and from the fact that 

 this peculiar mode of brecciation obtatued 

 in both regions, I wish to suggest that the 

 light brown or gray, amorphous, shaley 

 limestone of southwestern Missouri may be 

 the equivalent of the Cedar valley lime- 

 stone of central Iowa. 



Oscar H. Heeshey. 

 Galena, Mo. 



CURRENT NOTES ON PHYSIOGRAPHY ( X. ) 



ley's cloudland. 

 This long expected work (Stanford, Lon- 

 don, 1894. 208 p.) is an effort to establish 

 a classification and terminology of clouds 

 on a genetic basis. "While such a plan has 

 much to commend it, and must eventually 

 be adopted in fully developed form, its 

 presentation now is perhaps prematui-e ; for 

 there is yet much to learn regarding the 



origin of certain cloud forms, and much 

 difference of opinion still prevails on the 

 subject. Four chief classes are recognized^ 

 in Ley's scheme : clouds of radiation, such 

 as ground fogs ; of inversion, such as cum- 

 ulus, dependent on overturnings in an un- 

 stable atmosphere ; of interfret, such as 

 waving stratiform clouds formed at the con- 

 tact of layers of different temperature ; and 

 of inclination, such as pendent cirrus wisps, 

 caused by the settlement of particles from 

 one atmospheric stratum into another. The 

 illustrations, reproduced from photographs 

 by Clayden, are for the most part excellent. 

 The chief deficiencj' of the work is the ab- 

 sence of comparative tables, bj^ which the 

 terms proposed by Ley may be translated 

 into those adopted by the International 

 Meteorological Congress. In a number of 

 passages exceptions must be taken to the 

 manner of physical explanation of cloud 

 formation, especially to statements concern- 

 ing the relation of water and ice particles 

 in cumulus and cirrus clouds, and to the re- 

 peated implication that the liberation of la- 

 tent heat in the condensation of vapor ac- 

 tually warms the air. The chapters on the 

 theory of atmospheric currents and on the 

 prevailing winds of the globe are hardly 

 relevant to the rest of the book and add 

 little value to it. Remembering that the 

 author has devoted years of observation to 

 cloud study, and that latterlj'- his work has 

 been much interrupted by ill health, it is 

 doubly a regret that his book cannot be 

 more highly commended. 



BUREAU CENTRAL METEOROLOGIQUE. 



The latest series of Annales of this im- 

 portant Bureau contain as usual a volume 

 of memoirs in which, besides the statistical 

 studies of thunder storms in France by Fron 

 and several reports of magnetism, there are 

 essays by Angot on the advance of vegeta- 

 tion and the migration of birds in France 

 for ten years, 1881-1890, and on the meteor- 



