TERRESTRIAL GLOBE.
Peon. 1. "To find the latitude and longitude of any place." Bring the place to the graduated side of the first meri dian : then the degree of the meridian it cuts is the latitude sought ; and the de gree of the under the meri dian,is the longitude.
2. " To find a place, having a given latitude and longitude." Find the degree of longitude on the equator, and bring it to the brass meridian ; then find•the de gree of latitude on the meridian, either north or south of the equator, as the giv en latitude is north or south ; and the point of the globe just under that degree of latitude is the place required.
3. " To find all the places on the globe that have the same latitude and the same longitude, or hour, with a given place, as suppose London./' Bring the given place, London, to the meridian, and observe what places are just under the edge of it, from north to south ; and all those places have the same longitude and hour with it. Then turn the globe round; and all those places, which paSs just under the given degree of latitude on the meridian, have the same latitude' with the given place.
4. " To find the antceci, periceci, and antipodes, of any given place, suppose London." Bring the given place, Lon don, to the meridian, then count 51} the same degree of latitude southward, or towards the other pole, and the point thus arrived at will be the antceci, or where the hour of the day or night is al ways the same at both places at the same time, and where the season and lengths of days and nights are also equal, but at half a year distance from each other, be cause their seasons are opposite or con trary. London being still under the me ridian, set the hour index to twelve at noon, or pointing towards London ; then turn the globe just half round, or till the index point to the opposite hour, or twelve at night ; and the place that comes under the same degree of the meridian where London was shows where the perimci dwell, or those people that have the same seasons and at the same time as London, as also the same length of days and nights, &c. at that time, but only their
time or hour is just opposite, or twelve hours distant, being 'day with one when night with the other, &c. Lastly, as the globe standS, count down by the meridian the same degree of latitude south, and that will give the place of the antipodes of London, being diametrically under or opposite to it ; and so having all its times, both hours and seasons, opposite, being day with the one when night with the other, and summer with the one when winter with the other.
5. " To find the distance of two places on the globe." If the two places ,be ei ther both On the equator, or both on the same meridian, the number of degrees in the distance between them, reduced into miles, at the.rate of seventy English miles to the degree, (or more exactly sixty-nine and one-fifth,) will give the distance near ly. But in any other situations of the two places, lay the quadrant of altitude over them, and the degrees counted upon it, from the one place to the other, and turn ed into miles as above, will give the dis tance in this case.
6. " To find the difference in the time of the day at any two given places, and thence the difference oflongitude." Bring one of the places to the meridian, and set the hour index to twelve at noon ; then turn the globe till the other place comes to the meridian, and the index will point out the difference of time ; then, by al lowing fifteen degrees to every hour, or one degree to four miles of time, the dif ference of longitude will be known. Or the difference of longitude may be found without the time, thus : First bring the one place to the meri dian, and note the degree of longitude on the equator cut by it ; then do the same by the other place ; which gives the lon gitudes of the two places ; then subtract ing the one number of degrees f'rom the other gives the difference of longitude sought.