ON THE FACTS AND THEORY OF EARTHQUAKE PHENOMENA. 27 
or the region lying between the western slope of the Andes and the sea, 
from the 25° to the 45° south latitude, between the Desert of Atacama on 
the north, and the Archipelago of Chonos on the south. 
The following table contains his numerical results for a region, however, 
in which shocks of greater or less intensity are almost of daily oc- 
currence :— 
Tasie X1X.—Earthquakes of Chili and the basin of La Plata. 
Earthquakes with date of Day or Month. 
o 2 
Century. | | |; 8 wig ls é Total. 
| my ‘ as Re |/ Oo] 8 
eet ey eal] Slee ee ale Bs 
SeI(SI\SIEBIE| S13) P/B/8)5/3-4 
silelal@alals In jalalo|4aia 
YT. .s..-; | fie 2a <j is 1 ays 
BEVEL cane. Tae 1 si ae 6 9 
Vie) Lb} 1) 1 LP le Dee Mon! ae a ey LO 
XIX. 4|10,14) 8/19) 11] 16/15/16) 9) 27) 8| 38] 170 
Total .... 15 | 12} 16} 8] 21 | 12) 16) 16| 16) 10) 27} 9 | 16! 194 
Winter Spring | Summer Autumn 
43 41 48 46 
From this table he has omitted several earthquakes, whose period has 
been prolonged to several weeks or even months, by a convention like that 
adopted here with regard to the memoir of Comrie, &c. 
A table of earthquakes noticed as occurring in Peru from a.p. 1810 to 
1835, by M. Castelnau, was presented to the Academy of Sciences in 
1847, by Arago (‘ Comptes Rendus,’ 2 Nov. 1847) ; but the catalogue itself is 
not given, and I am not aware that it has appeared elsewhere. 
M. Lambert, mining engineer of Chili, in a memoir on the causes of 
earthquakes in Chili and Peru (‘Ann. de Chim. et de Phys.,’ t. xlii, 
pp- 392-405), published in 1829, mentions that the Chilians vulgarly 
divide their year into three seasons or ‘‘temporadas,” and that one of these, 
the first, composed of January, February, March, and April, is called “tem- 
porada de los tremblores,” or earthquake season; on comparing the facts of 
his catalogue, with the popular belief however, Perrey finds the facts pal- 
pably contradict it. 
As to the prevalent horizontal direction here, Perrey makes no attempt 
to discuss it, contenting himself. with the remark, that the popular belief 
is universal in the region, that it follows the chain of the Cordiilera. Ina 
country, however, having so little of its observed surface (for the great 
sandy deserts are nearly unknown as respects our inquiry) of a level cha- 
racter, with a general seaward -slope from the great central axis, and with 
the origin of disturbance so closely beneath, that many of the most for- 
midable earthquakes have emerged almost vertically over considerable 
tracts, the attempt to fix a prevailing horizontal direction would be 
nugatory. 
Finally, we come to the two last of Perrey’s memoirs which have been 
referred to—those in which he has brought under one view many of the 
facts of his monographs, and graphically discussed the results in tables 
for all Europe, with the adjacent parts of Africa and of Asia, and for the 
north of Europe with the north of Asia, viewed as one great boreal band. 
The results of the former are given in the following Table :— 
