428

1835 Valparaiso. Elevation land

line of the wall & the beach there is in one part a row of large houses & in another two rows separated by a street. — The vertical height (levelled by a civil engineer) is 11 ft 6 inches above the line of high-water on the sea-beach. +++ — I think It is unquestionable, that the largest fraction & the only perceptible fact only sudden rise, ever observed, was in 1822 & about3 ft:

Perhaps we may presume from the above account of the originally high wall, having been broken down, & yet the street being used, that some change took place between its foundation 1680 & its disuse about 1817.

However it appears certain that in years from 1817 to 20 the change must have been more marked, this is the period to which all the old inhabitants refer.

We then have the famous earthquake of 22. — But I believe it is beyond doubt, from the gradual appearance of parts of an old wreck, that the land has now subsequently in like manner as we have shown in Chiloe. — From the ruined state of the remnant of the wall, it is not possible to know whether the part now 11^ft 6 above high water, was in 1680 daily washed. (which is most probable) or only occasionally by the tides of the sea. — I must here remark on the coincidence of this measurement

428 verso

with the distinct observations of M^r Alison & myself on the sea coast both to the N & S of the town.

From those it is clear, that when the land was from 12-15 ft lower the sea for a long period beat on & excavated hollows as a in a certain band of rock. — That The church of San Augustin is believed to have been built in 1614, the base of its walls are 19^ft 6 (or 8 ft above the sea wall) above high water mark.

[calculation] 1614 [+] 220 [=] 1834

Hence we may feel certain, that the land has not risen more than 16 ft (this difference at least would certainly have existed for the protection of the foundationof the church) in 220 years. — Probably at the time the church was built the band of excavations in hard rock was in quiet prpgress. in this case church would have been 6 .. 6 above tidal action. —

(a) The rise even in the Bay of Valparaiso could not have been quite equal — because it is confidently asserted that part of a Fort, which was not visible from a certain spot, became within the line of vision after the shock of 22. —

Alison's paper