366 Reviews — JEayden^s Atlas of Colorado. 



tlie entire area of Colorado, and some adjacent parts of Utah, Arizona, 

 and New Mexico. These maps are also contoured, the contour lines 

 representing, approximately, intervals of 200 feet vertical. 



All these maps are very beautifully drawn and beautifully printed, 

 and are types of careful, clear, and excellent work. The colouring 

 is also admirably printed, with a wonderful transparency and even- 

 ness, and with really admirable " register." Altogether the execu- 

 tion of the sheets of this noble atlas leave nothing to be desired. 



We cannot pass on without noticing the two sheets of panoramic 

 views. We have had in this Magazine opportunitj' before now of 

 drawing attention to the really effective aid which such views give 

 to the student in a ready and clear understanding of the descriptions 

 of a country.^ And we think the simplest inspection of the few 

 given in this atlas will be quite sufficient to prove to any one the 

 immense value of such outlines in enabling those who have not seen 

 the districts, to realize the facts. Who can compare the curiously 

 broken and rugged outline of the quartzite group of the San Juan 

 Mountains as seen from the Eio Grande Pyramid (Sheet xx.) with the 

 peculiar serrated and jagged peaks of the trachytic mass of the La 

 Plata Mountains, looking east from Mount Hesperus, on the same 

 sheet, without carrying away with him a vivid conception of the two 

 areas, and without, at the same time, we may remark, being struck 

 with the vast difficulties the surveyors have had to contend with in 

 such work ? True : the ground is well visible, there is no dense 

 jungle and no thick undergrowth of impassable and deadly vegeta- 

 tion to interfere with his progress. But the very loneliness— the 

 conviction of desolation, would in itself numb the energies of many ; 

 and double honour is due to those whose unflagging interest in their 

 researches, and whose untiring devotion to their work, have enabled 

 them to complete this great task. 



It is too late now to devote any space to a more detailed examina- 

 tion of the geological information given on these maps. We shall 

 probably have other opportunities of returning to the subject. But 

 we could not avoid at once congratulating Prof. Hayden on the com- 

 pletion of this grand atlas, and on the success which has thus 

 crowned the labours of his very efficient and zealous staff. If any 

 sense of shame yet remain in some other Survey staffs, we cannot 

 help hoping that they may be excited, by the comparison, to a little 

 more earnest and single-minded devotion to their labours than has 

 of late years distinguished them. 



There is still an immense area before Prof. Hayden. And we 

 shall look with eagerness for successive atlases of the other " Ter- 

 ritories " also. 



It would be injustice to our American brethren to omit noticing, 

 with the highest approbation, the marked liberality with which the 

 costly and valuable labours of these State Surveys are distributed to 

 all who are likely to take a real interest in the subject, or can in any 

 way reciprocate by exchange of similar publications. There is not a 

 library of any value for the student of Natural Science in this country 

 1 See Geol. Mag. Decade II. Vol. V. April, 1878, p. 174, etc. 



