54 REVIEWS—NELSON’S ATLAS, AND WALL AND FAMILY MAPS. 
Nelson’s Atlas of the World: constructed from the most recent 
authorities ; with divisions and measurements in English miles. By 
Thomas Nelson, Jun., and Thomas Davies, C. E. 
Nelson’s Wall Maps. 
Nelson’s Family Maps. London and Edinburgh: T. Nelson & Sonse 
Under the direction of one of the most enterprising of British 
publishers, we have here produced an atlas and series of large and 
small maps, embracing some of the most useful improvements that 
practical sagacity and experience have recently contributed to the 
facilities of education. The points in which they differ from all 
previsus maps are not more admirably adapted to remove the difficul- 
ties they cope with, than they are simple. Like so much else that is 
of the most practical utility, the wonder is that such adjuncts to our 
school maps were never thought of by Geographers till now. 
The projection of the maps is a combination of the conical develop- 
ment, with that by which Flamstead successfully aimed at not only 
making equal spaces on the map represent equal portions of the 
earth’s surface, but also at admitting of correct measurements being 
made parallel to and perpendicular to the equator. In the combined 
system here adopted, the parallels of latitude are represented by con- 
centric segments of circles as in the conical development ; while, as 
in that of Flamstead, the degrees of longtitude are accurately laid off 
on each parallel, and the meridians are drawn through these points, form- 
ing curved lines convex towards the centre meridian. By this arrange- 
ment, while it possesses all the accuracy of Flamstead’s projection in 
the measurements of areas, and of distances parallel to, and perpendi- 
cular to the parallels of latitude, the diagonal measurements are more 
accurate. 
The next practical difficulty dealt with is the process resulting from 
the application of astronomical mensuration to the science of Geo- 
graphy. The ordinary mode of stating the geographical position of 
Toronto is: latitude 43 degrees, 39 minutes, North; longitude 79. 
degrees, 21 minutes, West. But this scientific language requires for 
all ordinary uses, to be translated into the speech of common life. 
Comparatively few can form any distinct idea of the relative distances 
and positions of places on the earth’s surface by their longitude and 
latitude. Impressed with this conviction, Mr. Thomas Nelson, one cf 
the authors of the new atlas, conceived the happy idea of applying to. 
geography asystem of mensuration by English miles; and thus by 
the employment of the language of common life, making maps more 
