At the time of the _Council of Nice_, when the terms were settled for observing of _Easter_, the _Vernal Equinox_ fell upon the 21st of _March_; but by its falling backwards 11 minutes every year, it was found that in _Anno_ 1582, when the kalendar was corrected, the Sun entered the equinoctial circle on the 11th of _March_, having departed ten whole days from its former place in the year: and therefore Pope _Gregory_ the XIIIth, designing to place the equinoxes in their situation with respect to the year, took these ten days out of the kalendar, and ordered that the 11th of _March_ should be reckoned as the twenty-first: And to prevent the seasons of the year from going backwards for the future, he ordered every hundredth year, which in _Julian_ form was to be a _Bissextile_, should be a common year, and consist only of 365 days; but that being too much, every fourth hundred was to remain _Bissextile_. This form of reckoning being established by the authority of Pope _Gregory_ XIII. is called the _Gregorian Account_, or the _New Style_; and is observed in all the countries where the authority of the Pope is acknowledged, and likewise by several nations of the reformed religion. There being now above an hundred years past, since the reformation was made in the kalendar, the _Gregorian_ account has accordingly got before the _Julian_ one day more than it was in the time of its institution, the difference between these two accounts being now eleven days; so that the first day of any month, according to that way of reckoning, is the 12th of the same month, according to the New Style. I shall conclude this section with a brief account of the Atmosphere. [Sidenote: _Atmosphere._] The _Atmosphere_ is that thin body of air which surrounds the Earth, in which the clouds hover, and by which in their descent they are broke into drops of rain; which sometimes, according to the warmth or coldness of air, are froze into _Snow_, or _Hailstones_. _Thunder_ and _Lightning_ are also made in the _Atmosphere_, and wind is nothing else but a percussion of the air, occasioned by its different density in different places. The benefits we receive from the atmosphere are innumerable; without air no earthly creature could live, as is plainly proved by experiments made by the _Air-Pump_; and the wholsomeness of a climate chiefly depends upon that of its air: If there was no atmosphere to reflect the rays of the Sun, no part of the heavens would be lucid and bright, but that wherein the Sun was placed; and if a spectator should turn his back towards the Sun, he would immediately perceive it to be quite dark, and the least Stars would be seen shining as they do in the clearest night; and the Sun immediately before his setting would shine as brisk as at noon, but in a moment, as soon as he got below the horizon, the whole hemisphere of the Earth would be involved in as great a darkness as if it were midnight.