Scientific Intelligence — Geology and Mineralogy. 189 



16. On the Transporting Power of Currents, By Professor W. 

 B. Rogers. — Professor W. B. Rogers remarked, that it was much 

 to be regretted that we were yet in possession of no certain data on 

 the subject of the transporting power of cui'rents. The usual state- 

 ments, affirming, that at a certain rate of motion a stream will carry 

 forward sand, at another gravel, &c., are evidently fallacious, as the 

 important condition of the smooth or rough configuration of the bot- 

 tom is not taken into account. The problem is one of great diffi- 

 culty, requiring an accurate determination of the velocity at the bot- 

 tom and sides of the stream, where in ordinary cases the slow trans- 

 porting action is in progress ; and this velocity, it is well known, 

 differs from that of the axis of the stream, and from the average 

 speed of tlie whole mass, which is the datum usually sought by the 

 engineer. The investigation of the subject systematically was urged 

 by Professor Rogers as of fundamental interest in geological as well 

 as hydrographical science, and he hoped that ere long the Association 

 would institute a series of researches with that view. — (Sillhnan'' s 

 Journal of Science and Arts ; Second Series, No. 13, vol. v., 

 p. 115.) 



•' 17. On the Occurrence of Ores of Mercury in the Coal Forma- 

 tion of Saarbrilck. By Herr Von Dechen. — In a lecture before the 

 Society of the Lower Rhine, Herr Von Dechen notices this singular 

 fact. These ores are, in general, very rare, and, in this place, occur 

 in the upper division of the carboniferous group in beds belonging 

 to the productive coal formation, or even to a higher part of the 

 series, in which previously they were not known to be found in 

 any part of the earth. In this district they are confined to its 

 eastern portion; Baumholder, in the district of St Wendel, being 

 the most western point where they have been found, the Kellerberg, 

 near Weinsheini, the most nortlaern, Nack, near Erbesliidesheim, 

 the most eastern. " They occur in veins ' in the normal beds of the 

 coal formation, in the melaphyres, the amygdaloids, and the felspar 

 porphyries ; these massive rocks lying within the range of the car- 

 boniferous strata. They are also found disseminated and in fissures 

 in beds of sandstone of this formation, as at Miinster-Appel and 

 Waldgrehweiler, wholly unconnected with true veins. The associa- 

 tion with the ores of mercury of certain claystones and hornstones, 

 which are not in general found so much developed in this formation, 

 is very j-emarkable. Within the limits mentioned, ores of mercury 

 have been observed in thirteen different localities, some of which 

 range in straight lines. The longest of these lines reaches from 

 Katzenbach, over the Stahlberg, Landsberg, near Obermoschel, to 

 the Kellerberg, and is about fourteen (three German) miles in ex- 

 tent. — (Geological Journal, No. 14, p. 33.) 



