carry them with your eye into any apartment you

go.

Observe, in the Map which we have been speaking of, a dotted line at the top part, 10 deg. (or one line from the meridian of London) to the W. or left hand; this is to take the whole of Europe into the top part of the Map, as that quarter extends from about 10 deg. W, to 62 E. and is separated from Africa by the Mediterranean and the straits of Gibraltar, running between that town and Tangiers, in Africa.

Look on the Map and you will see these towns nearly opposite, the first has about 5 deg. and the other 6 W. Ion. and but a few minutes difference of lat. therefore the same word will express the lat. of both, (36 deg.) You will find them alphabetically arranged in the table.

To put these places on the Wall.

Five deg. of W. lon. is just half way from the meridian of London, West, to the next division; and 36 degrees N. lat. will be a little more than half way between 30 and 40 in the hight of the Room. The lon. and lat. of Petersburgh is gaze maze, i. e. 30 deg. E. lon. and 60 N. lat. look to the right of the meridian of London for 30, and at the top of the Wall you have 60, the lat. see it on the Map.-Nankin, China, is 118 E. lon. and 32 N. lat. The corner of the first Wall to the right of the meridian of London, will be 90 degrees; to the next division on the second Wall be 100, the next 110, and to the next 120; we find the lon. then, near the meridian of 120 E. and a little more than half way up the Wall we have 32 N. lat. Kingston, in Jamaica, was pope bare, 77

W. lon. and 18 N. lat. To put it on the Wall. About two thirds beyond the 7th division on the W; Wall, you have 77 deg. then cast your eye on the meridian of London, and nearly as high as 20 will be the lat. 18 degrees N. and this is the spot on the Wall where this island may be fixed; and in the same way may any other place or island be transferred from a Map, &c. to the Wall occupying a space according to its dimensions. In like manner may the parallels of lon. and lat. be drawn for any places on paper, and those places inserted, if the longitudes and latitudes are known.

Here follow two Examples, one North, and the other South Latitude.

Exam. I.-Draw the parallels of lon. and lat. that will include Constantinople, Petersburgh, Suez, and Bagdad. (You will find these places in the table, with the words joined to express the longitude and latitude.) When you intend to lay down a country or places, you have nothing to do but consider the greatest N. and S. lat. and E. and W. lon. or in other words, what parallels of lon. and lat. the country or places you wish to insert lie between.-In the foregoing Example, Constantinople has the least E. lon. (29 deg.) and Bagdad has the greatest lon. (44 deg. E.) therefore, the first having less than 30 E. I must begin with the meridian of 20 deg. and Bagdad being more than 40 E. I must extend it to 50 deg. E. or the fifth meridian beyond London.-Suez is 30 deg. N. and Petersburgh 60, so that we find 30, and 60, the two extremes of lat.-all other places that you find lying between those parallels of lon. and lat. you may insert. The other Example is in S. lat. which

you cannot fail to understand, if you have read this last with attention.-See them all laid down in the following plate.

Observations on General Maps, and how to understand them.

A general Map is such as treats of many countries, as a Map of Europe, Asia, &c.

When you open a Map that you are unacquainted with, look along the top, and see if you can find the meridian of London in it, (which is always marked with an 0,) and if it is not there, observe if the numbers increase towards the right hand, for if they do, the whole of the Map is E. lon. as a Map of Asia, or China. On the contrary if the numbers are higher towards the left hand, it is W. lon. but if they increase both right and left, it is evident that the meridian of London will be found running somewhere thro' the Map, and shews it to possess both E. and W. lon. as the Map of Europe, England, &c.

To know at the first glance whether a Map is N. or S. latitude, or both.

Look at the side and observe if the numbers increase from the bottom towards the top of the Map, and if they do it is N. lat.-if the numbers are larger towards the bottom it is S. lat.-but if they increase upwards and downwards, it denotes the Map to have both N. and S. lat. and the Equator (marked 0) must run somewhere thro' the Map.— This is the case when North and South America are delienated on the same Map; for S. America will extend to about 55 degrees S. lat. and North America to nearly 80 degrees N. lat.

Examples for drawing your parallels of lon. and lat. see page 151.

Exam. I. Constantinople, 29 E.-41 N.-Petersburgh, 30 E. 60 N. Suez, 33 E.-30 N.-Bagdad, 44 E.--33 N.

Ex. II. St.Helena, 6 W.-16 S.-C. of Good Hope, 18 E.--34S.

St. Helena being W. lon. and the Cape East, we must of course have the meridian of London, somewhere in the interior part of the Map, which you will here perceive distinguished by a nought; so that you have 6 deg. W. and 20 E. and from 10 deg. S. to 40, which is sufficient to include these places, and all others lying between those parallels.

To face p. 152.