~ oe 
Parnes tee. 
‘ 
Miscellaneous Intelligence. . AAT 
10. On the Oscillations of Suspension Bridges; by J. H. Réurs, 
Esq., M. A., (Lond. Edin. and Dub. Phil. ii 
bridges, by vibration arising from the tramping of troops, gusts of wind, 
& 
&c., as well as to suggest means for obviating the mischief under those 
circumstances. ‘The following were some of the most remarkable re- 
sults arrived at :— ote 
ist. That if the tension at the ends of the chain where it is suspended 
be kept constant by allowing play at those points, the variation of ten- 
sion due to vibration at any other point of the chain will be but small. 
ndly. That if the chain be tied at the points of suspension so that it 
can have no motion there, a slight extent of vibration will produce com- 
paratively a great increase of tension. 
3rdly. That periodic forces, such as may be taken, for instance, to 
represent the effect of tramping in time of troops moving across the 
bridge, are dangerous in the extreme, as if they happen to coincide in 
period with any of the possible types of vibration, the extent of vibra- 
tion will increase continuously, till it ceases to be represented approxi- 
‘mately by a linear or even an equation of the second order; in this 
case, the chain will be divided by nodal points where there is no vertical 
will include the foliowing scientific men. For zoology and botany, 
as aid in zoology and botany, M. Arthur von Nordmann, son of the 
Professor ; for entomology, Dr. Meeklin, of the University of Helsing- 
fors; for mineralogy and metallurgy, M. LePlay, Engineer-in-chief of 
the mines of France, and a member of the Crimea ex edition, and for 
fifteen years the “ Conseil Technique” of the Siberian Mineral Explo- 
_rations under M. Demidoff; for mineral observations, vee &e., 
J. B. Laure ; for painter tof lanscapes, portraits, &e., 
natural history painter, M. Weight of Helsingfors ; and M. Alphonse 
Baudin, son of the admiral, will have charge of the journal of the voy- 
age. A geologist and another person for physics are yet to be appointed. 
—L’ Institut, No. 958, April 7, 1852. ; 
12. Rain in the Khassya Hills, Stns i yore etn oe 
52. )— iend, Professor am, in Ww 
eat emcn rack a sig ssya Hills, north of Calcutta, states 
previously well known to Drs. 
men; but as the facts were only 
