HOW MAPS ARE MADE. 427 



on the same scale, but with very different i)roi)ortious. These three 

 projectious are typical ones and the most conimonly used, but there are 

 many others. For tbose desirous of studying- the subject the best 

 work on it I know is the article by 3Ir. Taylor, in the flune number of 

 the Scottish Geofjrnjjhical Mayuzine of 181)0, and to that article I refer 

 til em. 



Map-making. — We have now seen how the traveller finds liis place 

 on the globe's surface, and how, wlien found, he can project or map tliat 

 information on a Hat sheet. We shall now see how a map will grow. 

 Imagine a slup sailing into unexplored seas and coming- to some 

 land, say an island. The navigator at once fixes his position in the 

 ship in latitude and longtitude. The navigator's instruments are the 

 sextant, the chronometer, and the mariner's compass. The general 

 idea of the mariner's compass is that it always points to the north; 

 but accurately this is not so. The general direction of the compass, or 

 the magnetic pole, is not the true north, but a spot very considerably 

 to the west of it, and, in fact, shifts continually; not only in different 

 places, but even in the same place, the direction changes from time to 

 time, as there are many local causes of disturbance. The navigator, 

 then, to fix true north, must find his meridian — that is, he must 

 observe the direction of a star or the sun when it culminates or comes 

 to the meridian, and from this observation he computes the amount of 

 local variation of the compass. In practice it is not the moment of 

 culmination he actually observes, but the statement is accurate enough 

 for the i»urpose of this popular description. Knowing the variation of 

 the compass, he can then take accurate bearings or directions to any 

 feature he desires to record. Two or more such bearings to (say) a 

 mountain, crossing each other from different known places, fix its posi- 

 tion on the map. 



The navigator. — We can now show how a country is mapped. Sup- 

 pose a ship visits this island, and fixes, by the ways already indicated, 

 a few latitudes and longitudes, and sails round it, fixing here and there 

 points on the coast, and perhaps taking bearings of some mountain, 

 then the island would be represented in an atlas with several points 

 fixed and joined by dotted lines. Nautical surveying is always done 

 with the sextant, which measures both vertical angles and horizontal. 



Explorer. — Following in the wake of the sailor comes the explorer. I 

 had intended, when I first sketched out this paper, to give an imaginary 

 explorer's map of a journey across this island, but I have the privilege 

 of showing you something so infinitely precious that I feel it would be 

 a piece of bathos to concoct a sham map. Here I have two of Dr. Liv- 

 ingstone's own original manuscrijit maps, made on his last journey, 

 kindly lent me for to-night by his daughter, Mrs. A. L. Bruce. Here 

 we have no conjectures as to what the traveller might do; here are the 

 real power, the actual materials of geography. Instead of imagining 

 what an explorer should take with liim, I mav mention Livingstone's 



