GEOLOGY AND MINERALOGY 55 
earliest rubble beds, and may be seen on « 
Shy Path,” opposite to the storehouse ^2d 
town. Another occurs in a bed of . ah forma in James- 
dred feet or more higher up on the ^ le ^ e .^ / or “ati°n, six hun- 
observatory on Ladder Hill. And 83010 ^ Slde ’ J ust behind the 
others, in a more or less perfect * ** W “ a 
Ihe lava beds which follow on the rubble and r , 
stated, at least sixty or seventy nmv he , V ! ° ' vhlch > as alt ’eady 
more in composition than either tl ^ couutecb vary so much 
time and space need £ Z a V ted Z Z ' ^ *? U * ** 
layers of lava which are seen above f! <: xaraiQa W The first 
eastern, and western coasts * ■ line alon g tb e northern 
Tom and Horse Point, Ire' ^ bctween Holdfast ’ 
compact basalt, containing very few^vities^h ' ° f * ^ denSe 
from a foot or two to ten n,. t “ ? I t S 5 the -> r vary m thickness 
few, some of them in these 1 f Ibet.^ Although the cavities are 
teresting relic of the 1L ' 86 i° We !i ^ asa ^ tic str ata contain a most in- 
-a watfr, wMelf h , 7 7 ™ ^ bci “« «1M with 
cally seal d up in he m g T 7 f 7^ has be “ 
at the blasting t “' 7 ? 7™ Kr *“ T** ** wWk *««ng 
the western hillside r I ] lC WOrks ’ in a quarry on 
ately Jamestown daring the operation’ imnfedi- . 
eur/onndL/ote oT 7 77 r ° Ck °° k ^ appeared 
split open bv fi * ^ u w® P ™~ shaped cavities which had been 
Ion- inmriso 7 ? S the bla st. Ihe water thus released from its 
but°bv 1 T ent WaS . not sufficient to admit of its being collected 
tolerablv appllCatl0n of tlie ton 2 ue > its nauseous flavour afforded 
those ro, g i°° d GVldenCe ° f lts rea % bein g sea water. Little were 
were revelri^VT ° f the extremel y interesting fact they 
of years before Id"' rZl * ^ had existence th ™ s ™ d » 
J nei 01 e, and which had been so carefully preserved h, r , + 
throngh all that time from any change. 3 P ty “ ature 
After several layers of this hard basaltic character i„ , i • , 
SXdtt °tL fel nT I r <1 ° m , i " atB - at “ ^Mejto 
et, the nature of the lava chan-es • and a cm„i a i, 
blue btalt differ i Dt 00m * K « i ? i ?“ intervenes, vis ’ a very heavy dal- 
and 7 • ’ mUC1 m ° re au 2 ltic m character than the lower basalts 
crystais ° f ^ “ a 
somet™ b ?' 7 ayers are a « ain ai ™ple basalt, only chan^d 
eometimes by strata of a more felspathic nature, suci as greyslne 
