RECORDS 53 



The following program was then offered : 

 Percival Lowell, Modern Mars. 



Summary of Papers. 



Map making began with Beer and Madler in 1840. Since 

 then many charts have been constructed of the planet. Some 

 of them are so old as to have been more or less forgotten, 

 some are so new as nbt yet to be known. Collection and com- 

 parison of such of these maps as have marked advances in the 

 subject lead to some not uninteresting conclusions. Such are 

 presented in the accompanying series. 



The series consists of twelve maps : 



1. Beer and Madler 1840 



2. Kaiser 1 864 



3. Dawes by Proctor 1867 



4. Resume by Flammarion 1 876 



5. Schiaparelli iS/Z 



6. Schiaparelli 1 879 



7. Schiaparelh 1882 



8. Schiaparelli 1884 



9. Lowell 1 894 



10. Lowell 1897 



1 1 . Lowell 1 899 



12. Lowell 1 90 1 



These maps fall naturally into three groups, dividing the his- 

 tory of areography into as many stages. 

 I. Those from 1 840-1 877. 

 II. Those from 1877-1892. 



III. Those from 1 892-1902. 



The maps of the first group are characterized by large 

 patches of light and dark areas. Maps 1-4 show these patches, 

 and by their agreement prove that the patches are permanent 

 in place. For the maps are the work of different observers 

 made at different epochs of time. 



The maps of the second group are distinguished by a net- 

 work of fine, straight lines covering the bright areas of the 



