DESCRIPTIONS OF STATIONS. 



As stated in the previous volumes, one of the chief difficulties experienced by 

 the observers of the Department of Terrestrial Magnetism, in the reoccupation 

 of old stations for secular-variation data, has been the lack of necessary informa Lion 

 to permit precise recovery of the point where the previous observations were made. 

 Owing to the frequent occurrence of local disturbance, it may readily happen that 

 erroneous secular-variation data will result from non-recovery of exact station. 

 Accordingly, the observers of the Department are instructed to furnish as complete 

 descriptions as possible of stations occupied, especially of such as give promise of 

 future availability. Information additional to that contained in the published 

 descriptions or copies of station-sketches or of photographs of surroundings will 

 gladly be furnished those who are interested in the reoccupation of any of the 

 stations. 



The descriptions are given in alphabetical order under the same geographical 

 divisions adopted in the Table of Results. The general form followed in the de- 

 scriptions is: Name of station, year when occupied, general location, detailed 

 location, distances and references to surrounding objects, manner of marking, and 

 finally the true bearings of prominent objects likely to be of permanent character. 

 All bearings, unless specifically stated otherwise, are true ones, and are reckoned 

 continuously from to 360, in the direction, south, west, north, east. For some 

 expeditions, owing to the absence of surrounding objects to which reference could 

 be made and to the nature of the country traversed, the descriptions of stations 

 naturally could not be made very full or precise; for some stations the data were 

 necessarily so meager that worth-while descriptions could not be made up at all. 

 When no mention is made of marking of station, it is to be understood that the 

 station was either not marked at all or not in a permanent manner. For those 

 stations which could properly be designated under more than one name, or which 

 had several names locally, appropriate cross-references have been made. 



The majority of the measured distances were made originally in the English 

 system; however, the distances obtained by conversion into the metric system are 

 also given, but inclosed in parentheses, so as to show that they are converted 

 figures. The following rules have been adopted in the conversions: Distances 

 given to 0.01 foot are converted to the nearest 0.001 meter, 0.1 foot to the nearest 

 0.01 meter, 1 foot to the nearest 0.1 meter, estimated feet or yards to nearest meter, 

 estimated fraction of a mile to nearest 0.1 kilometer, estimations of more than a 

 mile to nearest kilometer. Short and important reference distances, when measured 

 accurately, have been converted into nearest 0.1 centimeter; such measurements, 

 however, as, for example, dimensions of marking-stones, etc., which are not of 

 great importance, have been converted to the nearest centimeter. If a distance is 

 given immediately preceding an azimuth of a mark, it is to be interpreted as dis- 

 tance from the magnetic station to the mark; it is in general estimated. 



223 



