3§6 POPULAR SCIENCE MONTHLY. 



the old too has often remained either unknown or ignored, buried in 

 the books which nobody reads. Thus the whole chain of argument 

 is rarely available to those not engaged in the investigation, and the 

 conclusions reached appear to hang on slenderer threads than is really 

 the case. It has seemed to me, therefore, not without profit to collect 

 into one the various views of the cartography of Mars, so much, 

 that is, as is essentially original and not mainly confirmative of the 

 work of previous observers. To this intent, I have produced the new 

 maps, reproduced the old and set them opposite one another. Thus 

 brought face to face they make a rather impressive self-confessed avowal 

 of relationship. 



Twelve maps constitute the series. Each marks the point 

 areography had reached at the time. No map has been left out which 

 added anything new except when a contemporary added more. The 

 twelve maps arranged in chronological order are these : 



I. Beer and Madler, 1840. 



II. Kaiser, 1864. 



III. Dawes by Proctor, 1867. 



IV. Resume by Flammarion of all to date, 1876. 

 V. Schiaparelli, 1877. 



VI. " 1879. 



VII. " 1882. 



VIII. " 1884. 



IX. Lowell, 1894. 



X. " 1897. 



XL " 1899. 



XII. " 1901. 



As is commonly the case when things are summed up, much more 

 results than one anticipates. It always turns out that one has spent 

 more than he imagines ; and fortunately with accumulations it is some- 

 times the same. Much emerges thus from the present assemblage 

 and three points in particular stand out to command attention. The 

 three points will be found to be: 



1. The fundamental agreement of the whole series. 



2. Evidence that the peculiarity of the markings seen by Schia- 

 parelli was not the fathering of fancy, but a recognition forced upon 

 him by the markings themselves. 



3. A visible evolution in discovery which has steadily progressed 

 from the beginning to the present day marked by three stages — pre- 

 Schiaparellian, Schiaparellian and what we have learned since. 



To be struck by these three deductions it is only necessary to com- 

 pare the several maps with one another when one shall have learnt so 

 much of the circumstances of each as to make their relations under- 

 standable. 



