Mineralogy and Geology. 115 
__ I. Mineraroey anp Groxoey. 
Per On the Wave of Translation in connexion with the Northern Drie j 
y W. WueweEit, D.D., F.G.S., (Lon. Quart. Jour. Geo. Soc., Aug. 
i“ 1847. )—The great geological problem of the “ Northern Drift” has been 
‘ view is pres n the ‘ Geology of ‘Reis sia” “ah "Sit oderick 
r Murchiso e are pee very simple numerical calculations which 
1 belong to this waa and which may throw some light on the proba- 
bility of such a theory. These calculations must necessarily be hypo- 
thetical as to their ane tities, but as to their quantities only ; and even 
these ht be capable of correction by a more careful survey of i facts. 
ia aity 
now to be consi 
‘It has been statdd to the Geological Society, that, by ‘Napposihe the 
‘sudden elevation of a submarine district, there is no ulty in account- 
ing for a . of twenty-five or thirty miles an hour ni the bottom of 
the sea, consequence of the “ wave of translation.” In makin 
this aserion, I think it has not been sufficiently considered that what 
is thus called a * ate Sy * is really a transient motion for each point of 
~ the AD of the wa The great wave is solitary ; the fluid before 
-and behind it is at eed and the particles move only while the wave is 
as it passed over each, moving each but a small distance. A single 
~ wave of translation bait explain the situation of a long Jine of masses 
each of which is moved through a great distance. 
If indeed we suppose a series of waves of translation each produced 
by: a sudden elevation, or by some other paroxysmal action, we may ob- 
In the operation of such a 9 ttery, each shock 
a of the wave, and 
by pio such ee 
for. 
cs 
tgs ae 
is eit 
7 
