HOW MAPS" ARE MADE. 433 



known; to eliniinate manifest errors, to reduce to scale and to projec- 

 tion uniform with his great maps of the same part of tlie world, and 

 generally to make everything shipshape for publication. 



Atlas-maMng. — I do not here refer to the Ordnance Survey maps, 

 drawings, and prints, which were described with the utmost detail and 

 j)recision by Sir Charles Wilson, but to the general atlases, such as 

 Johnston's and Bartholomew's. With the information so gleaned the 

 cartographer is able to make those beautiful orographical ma|)S, which 

 are now so common, showing different levels. 



In our diagram 1 have colored the island orographically, which is 

 done by drawing the contour lines and washing over the areas so 

 marked with different variations of tint. But I shall not go far into 

 this subject. Imagine the map drawn. It may be then engraved, 

 like any other picture or line engraving, on a copper plate, and either 

 printed from that plate or from lithographic stones, to which an im- 

 pression of the plate has been transferred. 



In the ( )rdnance Survey printing oftice, instead of lithographic stone, 

 the maps are printed from sheets of zinc, which has much the same 

 property of absorbing greasy ink. 



By this time we have got into the printing othce, and to describe it 

 in detail would be beyond my province. This part of the subject though 

 very interesting, really embraces the whole art of the engraver, the 

 lithographer, and the printer. But there is one process I desire to 

 show before closing. 



You see daily in books and newspapers, and in our own journal, maps 

 printed in black along with the type. There are numberless processes 

 for their production; one only I shall briefly note. It is in the type- 

 process of Messrs. Walker »S: Boutall, who have kindly sent me a speci- 

 men in course of manufacture. 



On a brass plate a coating of a waxy composition is laid; the outlines 

 of the map are either drawn on this coating or photographically trans- 

 ferred to it. The engraver then scratches through the wax down to 

 the brass with a needle. He next takes suitable types and stamps in 

 the names also down through the wax to the brass, and comi^letes the 

 matrix with the necessary amount of detail, which may be great or 

 little. After verification and correction the matrix is readj^ for electro- 

 typing. You who know the appearance of stereotype molds will see 

 that this resembles the mold of an ordinary stereotype or electrotype 

 page. The mold is next covered with black lead and an electrotype 

 taken from it, when all the punctures that have been made through the 

 wax to the level brass plate come ont level — the scratches as lines and 

 the type as lettering. It is then mounted on wood, and is ready to insert 

 among type and be printed along with it. 



I have tried to give you very roughlj' an outline of how maps are 

 made from the beginning to the end, in almost the same form that 

 actual necessity forced me to learn it for practical use. 

 SM 93 28 



