I ,
! !
o n th e R e v o lu tio n s o f th e E a r th ’s S u r f a c e ;— a c a se w h ic h h a s a lw ay s
a p p e a r e d to m e to b e th e s tro n g e s t e v e r a d d u c e d in fa v o u r o f th e th e o ry
o f a n o v e rw h e lm in g d e b a c le h a v in g ru sh e d , a t le a s t in t h a t c o u n try , o v e r
h ill a n d v a lle y . T h e fu rrow s a n d s c ra tc h e s in th e sam e d is tr ic t a re
p a ra lle l to e a c h o th e r , a n d h e n c e ru n in th e s am e d ire c tio n :— th u s , n e a r
E d in b u rg h , th e y e x te n d in a lin e a l it tl e n o r th o f we st a n d s o u th o f e a s t,
t h a t is p a r a lle l to th e v a lle y o f th e e s tu a r y ; b u t b o th to th e e a s tw a rd a n d
w e s tw a rd th e y d e v ia te from th is lin e b y m o re th a n h a l f a r ig h t a n g le ; a n d
o n th e s o u th -w e s t p a r t o f S c o tla n d th e y lia v e n o u n ifo rm d ire c tio n .
I n th e n o r th o f S c o tla n d , h ow e v e r, n e a r B ro ra , M r. M u rc h iso n {Geolog.
Transact. 2d Scries, v o l. ii., p . 3 5 7 ) fo u n d th e h ills m a rk e d in p a ra lle l
lin e s , d ir e c te d n o r th -w e s t a n d s o u th - e a s t. T h e fu rrow s a n d s c ra tch e s
n e a r E d in b u rg h se em g e n e ra lly to tra v e rs e th e less in c lin e d su rfa c e s, b u t
S ir J am e s , s p e a k in g o f o n e p a r t , says “ th e perpendicular fac e as w e ll as
th e r e s t is c o v e re d w ith lin e s , w h ic h a r e h o r iz o n ta l, o r n e a rly so.” I n
th e s e re sp e c ts th e ca se a p p e a r s v e ry s im ila r to t h a t o f th e A lp s : th e
ro ck s , h ow e v e r, a r e n o t p o lish e d ;* b u t th is m ay b e ow in g to th e i r n a tu r e ,
s a n d s to n e a n d t r a p , a n d n o t to a n y d iffe re n c e in th e c a u se ; fo r D r .
R ic h a rd s o n te lls me t h a t in th e sam e riv e rs in N o r th A m e ric a , in w h ic h
th e g r a n itic ro c k s a r e m u c h p o lish e d , th o s e o f lam in a te d lim e s to n e a r e
n o t a t a ll so . N e a r E d in b u rg h , w h e r e th e lin e s e x te n d w e s t a n d e a s t,
th e w e s te rn fac e o f th e h ills (o f w h ic h th e h ig h e s t m e n tio n e d is fo u r
h u n d r e d a n d s e v e n ty f e e t a b o v e th e se a) is c h ie fly m a rk e d , w h ils t o n th e
o p p o s ite o r p ro te c te d s id e , a lo n g ta il o f (so c a lle d ) diluvium e x te n d s ,
w h ic h c o n s is ts o f b lu e clay , w ith la rg e e r r a tic b o u ld e r s em b e d d e d in it.
T h e s e b o u ld e r s , a s I am in fo rm e d b y M r. J am e s H a ll, a n d b y M r. Sm ith
o f J o rd a n h ill, a re th em s e lv e s m a rk e d w ith p a ra lle l lin e s , h a v in g o n e
d ire c tio n , w h ic h sh ows t h a t th e y w e r e h e ld fa s t w h ils t d r ifte d a cro ss th e
c o u n try , a n d n o t ro lle d o v e r a n d o v e r, lik e a p e b b le in a s tr e am . I t is
o f g la c ie rs in th e A lp s a n d in o th e r reg io n s o f c e n tr a l E u ro p e , e x c e p tin g
a t g r e a t a l t i tu d e s ; a n d from s u c h s itu a tio n s a d e b a c le w a s a b s o lu te ly
r e q u is ite to t r a n s p o r t fra gm e n ts o n ice . S ir J am e s re je c ts th e b e lie f o f
M , W re d e (g iv e n o n th e a u th o r i ty o f D e L u c ) , t h a t th e b o u ld e r s o f th e
B a ltic m ay h av e b e e n b ro u g h t in to th e i r p r e s e n t p la c e b y ice, a c tin g ,
d u r in g a s te a d y a n d s low c h a n g e in th e lev e l o f th e o c e an . M . W re d e ,
th e r e fo r e , a p p e a r s to h a v e b e e n th e o r ig in a to r o f th e th e o ry a d v o c a te d in
th is v o lum e ; a n d n o c o u n try was m o re lik e ly th a n Sw ed e n to h av e g iv en
b i r th to su c h a th e o ry .
* I t is, h ow e v e r, s a id _ in P ro fe s so r B u c k la n d ’s Rcliquice Diluviance,
p . 2 02, t h a t C o lo n e l Im r ie fo u n d th e su rfa c e o f som e tra p - ro c k s in th e
s o u th e rn p a rts o f S tirlin g s h ir e , h a v in g “ a c o n s id e ra b le d e g re e o f p o l is h ;
a n d th is p o lish is a lm o s t a lw ay s s e e n m a rk e d b y lo n g lin e a r s c ra tch e s .”
a dm itte d b y a ll t h a t th e g ro o v es o n th e s o lid ro c k w e re fo rm e d hy th e
p a ssag e o f th e s e b o u ld e r s o v e r it. A lth o u g h th e m in o r in e q u a litie s o f
th e su rfa c e o f th e la n d a p p e a r to h a v e h a d n o in flu e n c e w h a te v e r o n .th e
a c tio n w h ic h p ro d u c e d th e sc ra tc h e s , y e t th e la rg e r fe a tu re s , a s th e
g e n e ra l h e a rin g o f th e m a in v a lley s , a p p e a r to h a v e d e te rm in e d th e i r
d ire c tio n . S ir J am e s d is tin c tly s ta te s t h a t th e s co o p in g s a n d fu rrow s h a v e
p re c ise ly th a t fo rm w h ic h th e lo n g a c tio n o f to r r e n ts te n d s to p ro d u c e o n
a so lid ro c k ; b u t h e ad d s, a n d I b e lie v e m o s t t ru ly , t h a t th e fu rrow e d
su rfa c e p ro d u c e d by su c h m e a n s is sm o o th , a n d n o t d e e p ly sc o re d a n d
s c ra tc h e d . I t is in d e e d u t te r ly in co n c e iv ab le t h a t la rg e s to n e s s h o u ld b e
c a rr ie d a lo n g as i f “ independently o f their gravity” b y a n y o rd in a ry m ean s ,
w i th su c h v e lo c ity , a s to m a rk w ith h o r iz o n ta l lin e s th e perpendicular
fac e o f a ro c k . F rom th e s e fac ts,— from th e p r e s e n c e o f g r e a t e rr a tic
b lo ck s , from th e s te e p n e s s o f o n e fac e o f th e g ro o v ed h ills, a n d th e
t a i l o f s e d im e n t s tr e tc h in g o u t from th e o th e r , S ir J am e s H a ll, h a v in g
in h is m in d th e r e c o rd e d cases o f th e g r e a t w a v e s c o n s e q u e n t o n e a r th q
u a k e s , in fe r re d t li a t a v a s t d e lu g e h a d b u r s t o v e r th e c o u n try from th e
w e s tw a rd .
M . B ro n g n ia r t, a n d la te ly M . S e fstrd in {L T n s titu t, February 2 2 d , 183 7 ),
h a v e d e sc rib ed p h e n om e n a in Sw ed e n a lm o s t id e n tic a l w ith th o s e o f S c o tla
n d . T h e ro ck s a r e th e r e g ro o v ed a n d s c ra tc h e d ,* e v e n to th e h e ig h t o f
1500 fe e t, in n o r th a n d s o u th lin e s , p a ra lle l to th e v a lle y o f t h e B a ltic a n d
o f th e G u l f o f B o th n ia ; b u t th e y a r e c o n s id e ra b ly ‘d e fle c te d b y th e
la rg e r in e q u a litie s o f su rfa c e . T h e n o r th s id e o f th e h ills a re m o s t a ffe c te d ,
w h ils t from th e s o u th e rn s id e , lo n g rid g e s, c a lle d oasars, s tr e tc h o u t ; th e y
a re com p o sed o f s a n d a n d w a te rw o rn m a te ria ls , a n d a p p e a r to b e s im ila
r, b u t o n a m u ch la rg e r scale, to th e tails o f diluvium in S c o tla n d . I n
Sw ed e n , h ow ev e r, th e e r r a tic b lo ck s a lw ay s lie o n th e su rfa c e o f th e s e
rid g es, a n d a re n o t em b e d d e d w ith in t h e m : b u t M . S e fstrom says, t h a t
a t th e tim e w h e n th e g ro o v es w e r e fo rm e d , e n o rm o u s masses o f ro c k w e re
to rn from th e m o u n ta in s . I n th e U n ite d S ta te s , th e p h e n om e n o n o f th e
g ro o v ed ro ck s a p p e a r s to b e d e v e lo p e d in a n e x tr a o rd in a ry m a n n e r . P ro -
* M r. L y e ll, m o re o v e r, d e scrib es {Philosoph. Transact., 1835, p . 18),
th e ro ck s o f g n eiss o n th e b e a c h n e a r O r e g ru n d in Sw ed e n , as b e in g so
“ sm o o th a n d p o lish e d , t h a t i t is d ifficu lt to w a lk o n th em .” F u r th e r o n
( p . 2 1 ), h e d e scrib es th e la rg e b o d ie s o f ice , w h ic h a r e a n n u a lly p a c k e d
o n th is c o a st, so as to b e e ig h te e n f e e t th ic k : h e re th e n w e h a v e th e
same p h e n om e n a as in th e A lp s ; a n d g r e a t ice b e rg s in m o v em e n t, in s te a d
o f so lid g la c ie rs . M o re la te ly M . B e r z e liu s h a s s e n t s p e c im en s o f th e s e
ro ck s, “ p o lish e d as i f b y em e ry in a c o n s ta n t r e c tilin e a r d ir e c tio n ” {Ed'mb.
Nciu Phil. Journal, v o l. 1., p . 3 1 3 ) , to P a r is , a c c om p a n ie d b y a l e t t e r to
M . E l ie de B e a um o n t.