municated with each other by small conductors. The first of them, attacked by some portion of water, &c. having taken fire, the igneous matter was successively imparted to the following ones, which, by their explosions, and by the collision and precipitation of the detached fragments, represented the discharges of artillery.
On the 26th of December, a shock of an earthquake, the most considerable which had occurred in the course of the year, was felt in Lima. Its duration was one minute thirty seconds, somewhat more or less; and its direction S. E., N. W.
According to Don Antonio Ulloa, the continual vapours by which the sky is obscured, in the winter season, in every part of low Peru, are occasioned by the prevalence of the north winds; but this opinion is controverted by a correspondent of the Peruvian Mercury on the following grounds. That, in 1791, on the days when the dews fell abundantly, as well as on those which preceded them, the winds blew constantly from the S. and S. W., and not from the N. The cause of the above phenomenon was not therefore to be ascribed to the latter winds. "It may be objected," he observes, "that these winds, having a considerable elevation, may not be perceived in the lower part of the atmosphere, their operation being entirely confined to the higher part. This might be granted, provided the southerly winds had ceased to blow in the inferior region of the air; but as they have been unremitting, and have maintainedthe same disposition as in the preceding seasons, a similar objection cannot be allowed. The blowing of contrary winds, even although one should be inferior, and the other superior, instead of fixing the vapours, would dissipate them, and would prevent them from being condensed, which can alone enable them to produce the wetting fogs."
