162 The Andes and the Amazon. 



of increasing activity, but in the summer became quiet again. 

 Cotocachi and Sangai, 200 miles apart, were awaked simul- 

 taneously ; the former, silent for centuries, sent forth dense 

 masses of earth and volcanic matter to a distance of many 

 miles, covering thousands of acres ; the latter thundered 

 every half hour instead of hourly, as before. Still, the 

 greatest earthquakes do not occur in the vicinity of active 

 volcanoes. Lisbon and Lima (where, on an average, forty- 

 five shocks occur annually, and two feai-ful ones in a cen- 

 tury) are far distant from any volcanic vent ; likewise North- 

 ern India, South Africa, Scotland, and the United States. 



An earthquake is beyond the reach of calculation. Pro- 

 fessor Perrey, of Dijon, France, is endeavoring to prove 

 that there is a periodicity in earthquakes, synchronous with 

 that in the tides of the ocean, the greatest number occur- 

 ring at the time of new and full moon.* If this theory be 

 sustained, we must admit the existence of a vast subterra- 

 nean sea of lava. But all this is problematical. Earth- 

 quakes appear independently of the geology of a country, 

 though the rate of undulation is modified by the mineral 

 structure. Earthquake waves seem to move more rapidly 

 through the comparatively undistnrbed beds of the Missis- 

 sippi Yalley than through the contorted strata of Europe. 

 Meteorology is unable to indicate a coming earthquake, for 

 there is no sure prophecy in sultry weather, sirocco wind, 



* Professor Quinby, of the University of Rochester, has, at our request, cal- 

 culated the position of the moon at the late earthquake: "August 16th, 1868, 

 1 A.M., the moon was on meridian 137° 21' east of that of Quito, or 42° 39' 

 past the lower meridian of Quito, assuming the longitude of Quito west of 

 Greenwich to be 79°, which it is very nearly. This is but little after the ver- 

 tex of the tidal wave should have passed the meridian of Quito, on the suppo- 

 sition that the interior of the earth is a liquid mass. The age of the moon 

 at that time was 27. 36 days, i.e., it was only about two days before new moon. " 

 At the time of the earthquake, 8 a.m., March 22, 1859, the moon was on me- 

 ridian 2.'>° 48' east of that of Quito, and was 17.6 days old. Shocks have 

 since occurred, March 20th at 8 a.m., and April 10th at 8 a.m., 1869. 



