of May; in the beginning of July the plants are in flower, and perfect their seeds in a month's time: for, though the sun is much more oblique in the higher latitudes, than with us, his long continuance above the horizon is attended with an accumulation of heat exceeding that of many places under the torrid zone; and there is reason to suppose, that the rays of the sun, at any given altitude, produce greater degrees of heat in the condensed air of the polar regions, than in the thinner air of this climate.

Yet, if we look for heat, and the remarkable effects of it, we must go to the countries near the equator, where we shall find a scenery totally different from that of the frigid zone. Here all things are upon a larger scale than in the temperate climates: their days are burning hot; in some parts their nights are piercing cold; their rains lasting and impetuous, like torrents; their dews excessive; their thunder and lightening more frequent, terrible, and dangerous; the heat burns up the lighter soil, and foams it into a sandy desert, while it quickens all the moister tracts with incredible vegetation.

The ancients supposed that the frigid zone was uninhabitable from cold, and the torrid from the intolerable heat of the sun; we now, however, know that both are inhabited. The sentiments of the ancients, therefore, in this respect, are a proof how inadequate the faculties of the human mind are to discussions of this nature, when unassisted by facts.

1

OF THE ANCIENT DISTINCTION OF PLACES BY THE

DIVERSITY OF SHADOWS OF UPRIGHT BODIES AT

NOON.

When the sun at noon is in the zenith of any place, the inhabitants of that place were by the ancients called ascii, that is, without shadow: for the shadow of a man standing upright, when the sun is directly over his head, is not extended beyond that part of the earth which is directly under his body, and therefore will not be visible.

As the shadow of every opake body is extended from the sun, it follows, that when the sun at noon is southward from the zenith of any place, the shadow of an inhabitant of that place, and indeed any other opake body, is extended towards the north.

of

But when the sun is northward from the zenith of any place, the shadow falls towards the south.

Those are called amphiscii, that have both kinds of meridian shadows.

Those, whose meridian shadows are always projected one way, are termed heteroscii,

PROBLEM XXI. To illustrate the distinction of ascii, amphiscii, heteroscii, and periscii, by the globe.

Rectify the globe to the summer solstice, and move the artificial horizon to the equator, the north point will be the most elevated at noon.

Which shews, that to those inhabitants who live at the equator, the sun will at this season appear to the north at noon, and their shadow will therefore be projected southwards.

But if you rectify the globe to the winter solstice, the south point being then the uppermost point at noon, the same persons will at noon have the sun on the south side of them, and will project their shadows northwards.

Thus they are amphiscii, projecting their shade both ways; which is the case of all the inhabitants within the tropics.

The artificial horizon remaining as before, rectify the globe to the times of the equinox, and you will find that when this horizon is under the strong brass meridian, a line going vertically upwards will be perpendicular to it, and consequently the sun will be directly over the heads of the inhabitants, and they will be ascii, having no noon shade; their shadow is in the morning projected directly westward, in the evening directly eastward.

The same thing will also happen to all the inhabitants who live between the tropics of Cancer and Capricorn; so that they are not only ascii, but amphiscii also.

Those who live without the tropics are heteroscii; those in north latitude have the noon shade always directed to the north, while those in south latitude have it always projected to the south.

The inhabitants of the polar circles are called peris

cii; because, as the sun goes round them continually, their shade goes round them likewise.

OF ANCIENT DISTINCTIONS FROM SITUATIONS.

These terms being often mentioned by ancient geographical writers to express the different situation of parts of the globe, by the relation which the several inhabitants bore to one another, it will be necessary to take some notice of them.

The antoci are two nations which are in or near the same meridian; the one in north, the other in south latitude.

They have therefore the same longitude but not the same latitude: opposite seasons of the year, but the same hour of the year; the days of the one are equal to the nights of the other, and vice versa, when the days of the one are at the longest, they are shortest at the other.

When they look towards each other, the sun seems to rise on the right-hand of the one, but on the left of the other. They have different poles elevated ; and the stars that never set to the one, are never seen by the other.

Perioci are also two opposite nations, situated on the same parallel of latitude.

They have therefore the same latitude, but differ 180 degrees in longitude; the same seasons of the year, but opposite hours of the day; for when it is twelve at night to the one, it is twelve at noon with

the other. On the equinoctial days, the sun is rising to one, when it is setting to the other.

Antipodes are two nations diametrically opposite, which have opposite seasons and latitude, opposite hours and longitude.

The sun and stars rise to the one, when they set to the other, and that during the whole year, for they have the same horizon.

The day of the one is the night of the other; and when the day is longest with the one, the other has its shortest day.

They have contrary seasons at the same time; different poles, but equally elevated; and those stars that are always above the horizon of one, are always under the horizon of the other.

PROBLEM XXII.

To find the Antœci, the Periæci, and the Antipodes of any place.

Bring the given place to the strong brass meridian, then in the opposite hemisphere, and under the same degree of latitude with the given place, you will

find the Antœci.

The given place remaining under the meridian, set the horary index to XII; then turn the globe, till the other XII is under the index, then you will find the Perioci under the same degree of latitude with the given place.

Thus the inhabitants of the south part of Chili are Antœci to the people of New England, whose Pericci are those Tartars who dwell on the north bor