ON THE FACTS OF EARTHQUAKE PHZ NOMENA. 25 
In commencing a Report upon the facts of earthquakes, it would be de- 
sirable, if possible, first to discuss and state the distribution of their occur- 
rence both in time and in space upon the earth: for either of these, however, 
complete data are not yet in existence ; no catalogue of earthquakes has ever 
yet been compiled which endeavours to embrace in number and condi- 
tion those recorded even since the invention of printing. The completest 
catalogue that could be compiled would not give much more than the places 
convulsed and the dates of the occurrence approximately ; yet such would 
not be without important use, and I have accordingly made considerable 
progress in the laborious task of having such a catalogue prepared, and 
trust to be enabled to give the results of its completion and discussion in a 
second part of the present Report at a future meeting. Meanwhile I may 
state (provisionally) that ) 
Ist. Earthquakes occur over all parts of the earth’s surface, both 
on land and under the ocean. 
Egypt was one of the countries long believed to be free from earthquakes, 
from which no doubt, like many other parts of the world, it enjoyed during 
a long historical period a considerable immunity. But that even Egypt has 
been absolutely exempt from earthquakes, seems disproved by the scattering 
of the gigantic ruins of the Memnonium, bearing all the marks of having 
_ been thus overthrown, and by the distinct testimony of Strabo, that one 
᾿ς of the two colossal figures of the plain of Thebes was commonly said in his 
_ time to have been overthrown by an earthquake :— 
“ ἐνταῦθα δὲ δυοῖν κολοσσῶν ὄντων μονολίθων ἀλλήλων πλησίον, ὁ μὲν 
σώζεται, τοῦ δ᾽ ἑτέρου τὰ ἄνω μέρη τὰ ἀπὸ τῆς καθέδρας πέπτωκε σεισμοῦ 
γενηθέντος, ὥς φασι.᾽᾿---ϑέγαῦ. Rer. Geogr. lib. xvii. 
The question of earthquakes occurring in Egypt is set at rest however by 
Bishop Pocock the traveller, who tells us in his ‘ Description of Egypt,’ p. 195, 
“It has hardly been known that they had any earthquakes in Egypt, but 
in January 1740 they had three great shocks, which threw down mosques 
_ and several houses.” 
2nd. They occur in all time, at all seasons, and at all hours of 
day and night. 
᾿ς So that were we able to survey this planet’s history in all time, we should 
find no portion of its crust which had not at some period or other been 
convulsed by earthquakes ; and could we have intelligence constantly from 
over its entire surface, we should find that no day passed free from one or 
many of these phenomena. 
ο΄ Seneca, in a passage as remarkable for its truth as for the dignity of its 
| expression, affirms his belief in the universal dominion of change, and of 
earthquakes over all the earth :— 
τ΄ “Omnia ejusdem sortis sunt, etsi nondum mota tamen mobilia; erramus 
| enim si ullam terrarum partem exceptam immunemque ab hoc periculo 
 credimus: omnes sub eadem jacent lege, nihil ita ut immobile esset natura 
-concepit : alia temporibus aliis cadunt ; et quemadmodum in urbibus magnis 
‘une hec domus, nunc illa suspenditur, ita in hoc orbe terrarum, nunc hee 
pars facit vitium, nunc illa. Tyrus aliquando infamis ruinis fuit. Asia duo- 
decim urbes simul perdidit. Anno priore Achaiam et Macedoniam que- 
cunque est ista vis mali que incurrit nunc Campaniam lesit. Circuit fatum, 
et siquid diu preteriit repetit. Quedam rarius solicitat, sepius quedam : 
_ nihil immune esse et innoxium sinit. Non homines tantum, qui brevis et 
_ caduca res nascitur; urbes oreeque terrarum et litora et ipsum mare in ser- 
