FINAL ACT OF SECOND PAN AMERICAN SCIENTIFIC CONGRESS. 57 



and hence upon the latitude and longitude of the place of observation. 

 The development of our knowledge of the shape of the earth has passed 

 the first and second stages of approximation, the first approximation 

 being a spherical surface and the second being a spheroidal surface of 

 revolution. The third approximation, known as the geoid, requires for 

 its determination an extended gravimetric survey in combination with 

 the geodetic measurements already referred to. 



A prime requisite in connection with the practicability of these projects 

 is a knowledge of the costs involved. The work contemplated will 

 require several decades, aggregating perhaps a half century, for its accom- 

 plishment. Hence it was desirable in the discussions to have presented 

 data derived from recent experience on the costs of the principal items 

 essential in such work. Accordingly, a member of the Section furnished 

 elaborate statistics for each of these items, along with indications of ways 

 and means which should be pursued in order to secure the requisite 

 efficiencies at minimum costs. 



ARTICLE 4. The Second Pan American Scientific Congress recommends 



that 



The Nations of the American Continent establish, by means of their 

 offices of geodesy or by committees appointed for that purpose, 

 an international triangulation; 



The Governments of the American Nations reach an agreement for 

 the purpose of creating an office or congress of cartography 

 and geography. 



In framing the program for the Engineering Section of the Congress, 

 which proposed this undertaking, it was deemed best to limit topics for 

 discussion to those which seemed to be of the greatest immediate mutual 

 interest to Pan America, to give special prominence to the matters which 

 had been considered at previous Congresses, and especially to those 

 referred by the First to the Second Pan American Scientific Congress. 

 Under such circumstances particular attention was given to matters 

 pertaining to transportation, to electrical engineering, to reclamation, 

 irrigation and drainage, to sanitary and municipal engineering, and to a 

 few topics of mechanical engineering, omitting as of lesser importance 

 all subjects which might be considered theoretical rather than practical. 

 The topics above mentioned were later enlarged by the addition of 

 others of a miscellaneous nature, such as standards, surveys, public 

 parks, public buildings, and special engineering work of governmental 

 departments or bureaus. 



