MAPS 197 



traveler in little known regions often afford valuable clues, and sometimes 

 they are the only ones we have. 



MAPS 



The maps of Brazil, like those of other countries, are not all good. 

 There is no trustworthy large scale general map of the conntry. Some 

 of the states have no surveys and are poorly provided with maps ; others 

 have lately nndertaken good topographic maps, notably Sao Panlo and 

 Minas Geraes. The Sao Paulo topographic maps are on a scale of 1 to 

 100,000, with 25 meters contour intervals, and five sheets have now been 

 published. The topographic maps of Minas G-eraes are on a scale of 1 to 

 100,000, with 50 meters contour intervals; ten sheets have been pub- 

 lished. Of late years the need of trustworthy maps compelled the In- 

 spectoria de Obras Contra as Seccas to make their own maps of several 

 of the northern states in which drouths occur, notably in Piauhy, Ceara, 

 Eio Grande do Norte, Parahyba, Pernambuco, Sergipe, and Bahia, and 

 though made mostly by horseback meanders, are noteworthy as being the 

 most valuable additions made of late years to the cartography of those 

 states. This work was planned and carried out by the distinguished 

 Brazilian geologist and engineer. Dr. Miguel Arrojado E. Lisboa, while 

 he was director of the Inspectoria de Obras Contra as Seccas, and these 

 maps have been our chief source of information in regard to the geo- 

 graphic details of the states so mapped. 



In 1913 the Inspectoria Federal das Estradas, under the inspectorship 

 of Dr. Jose Estacio de Lima Brandao, published a valuable modern atlas 

 of the railways of Brazil; but the sheets are on various scales and are 

 hardly available for the purposes of geologists. The atlas of Homen de 

 Mello gives as good maps of the states as can be had on a small scale. 

 The first edition of his work was published in 1882; the last in 1909. 

 There are maps of most of the states, some of them remarkably good in 

 view of the lack of trustw^orthy data for their construction. 



The base map used for the geology has been compiled especially for the 

 purpose by using all available data, in so far as it can be shown on a 

 map of this scale. Dr. L. A. Bauer, Director of the Department of Ter- 

 restrial Magnetism of the Carnegie Institution, has kindly furnished me 

 all the available determinations of latitude and longitude made under his 

 direction in Brazil. I have also had the determinations made under Dr. 

 H. Morize, director of the astronomical observatory at Eio de Janeiro, 

 besides the results of the magnetic survey of eastern Brazil by Dr. Van 

 Eyckevorsel and E. En^-elenburo-, published at Amsterdam in 1890. 



Unfortunately it is impossible at present to tie into this network many 



