To Societies and Collectors. 59 



The results herein embodied were obtained from the collections of 

 Mansfield, Drake, Ra^', Lea, Harper, Phillips, Farmers' College, and U. 

 S. Signal Service Office, Cincinnati. While those of Prof. Harper are 

 preferred as means, those of R. C. Phillips, civil engineer, Ibr a portion 

 of the same time, arc of special interest, taken at lower elevation, and 

 more nearly central in lower plane of the city ; they aA^erage higher, 

 owing to locality. This series, taken at elevations not materially dif- 

 ferent from this room, maj' be considered reliable., and as Jflling a 

 want, that of uniformity, not likel}' to occur again, as they will be 

 regularly and uniformly taken and properl}- arranged hereafter. Our 

 city, situated at intersection of longitudinal and transverse valleys, its 

 lower plane mostly surrounded by an amphitheatre of hills, has local 

 and eddying currents, with an atmosphere heavily charged at times 

 from the consumption of soft, bituminous coal. These occasionally 

 effect locally, both radiation and condensation; while changes and va- 

 riations of both temperature and precipitations are great, the averages 

 are verj' nearly the means, 43.3 inches, for the whole Ohio Valley, 214,- 

 000 square miles; the indications are secular changes in a series of j'cars, 

 but until we have more full and complete reports from other districts, 

 for comparison with our own, the great problem of what ratio of less 

 precipitations, with all its pai-amount influence on agriculture, com- 

 merce and manufactures, remains unsolved. In the cause of Science 

 and Philanthropliy, we cheerfully accord our best efforts toward a full, 

 complete and reliable meterological record. 



TO SOCIETIES A]^D COLLECTORS. 



The Cincinnati Societ}' of Natural Historj^ is very desirous of 

 making exchanges in all its departments. Every society of this 

 character soon accumulates a large quantity of good material, in dupli- 

 cate, which become a burden instead of a benefit, unless thei'C is some 

 systematic way of disposing of the surplus stock. We desire to ofter, 

 at the present time, either to private collectors or public institutions, 

 the following exchanges : — 



1. Palaeontology. — It is well known that the Cincinnati Group, Lower 

 Silurian, as it is exposed at and near this locality, contains the best 

 preserved specimens that can be obtained anywhere. Several hundred 

 species have alread}^ been described, and we have any amount of 

 material for description in the future numbers of this Journal. We 



