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The National Geographic Magazine 



Eclipse Instruments, Guelma 



first been established, the former element 

 Dy the transit instrument and the longi- 

 tude by telegraphic comparisons of time 

 from the fine observatory at Algiers. 



Then the photographic dark-room, that 

 prerequisite of every eclipse station, was 

 assembled and put together for imme- 

 diate use in the development of photo- 

 graphs used in testing the instruments. 



Naturally the long forty-foot photo- 

 heliograph camera required considerable 

 time to put in place, for besides its in- 

 stallation it had to be covered by screens 

 to protect it from the rain, sunshine, and 

 strong winds. 



An equatorially mounted telescope, to 

 be used by the director general of the 

 camp, was mounted in a central position, 

 which commanded a view of all the in- 

 struments under his control. 



During the time the instrumental in- 

 stallation was going on, one of the party 

 strayed away from the camp and fell into 

 the hands of the Arabs of this desert 

 country, but it is apparent he was not 

 treated as inhumanely as those other brig- 

 ands in Morocco treated our friend Mr 

 Perdicaris. One of the junior members 

 of this Arab party went so far as to pat 

 •our sailor man on the cheek. 



Probably the next most important in- 

 strument we have in the party is the grat- 

 ing spectrograph, under the charge of 

 Mr Jewell, of Johns Hopkins University. 

 It is difficult to conceive of the thought 

 and labor that has been expended upon 

 this instrument. An introduction of a 

 r ^ri <= n° iv th^ hn° ^f th*^ sun s ravs rjassins^* 

 through a lens to the photographic plate 

 is easily accomplished, but the fitting of a 

 grating which will give probably better 

 results is quite another affair. It is doubt- 

 ful if there be a piece of machinery so 

 carefully constructed as an engine which 

 cuts 20,000 lines to the inch on a piece of 

 metal which is necessary for this delicate 

 work. This must be done to make a 

 diffraction grating. 



Now we come to a picture of the artists 

 who are to draw the corona and its ex- 

 tensions, some of them being provided 

 with telescopes to extend their view of 

 the coronal streamers to the outer limits 

 of vision. Finally is seen the whole party 

 assembled around their completed in- 

 struments, with the tall form of Captain 

 Norris, the chief of the party, on the left. 



OUR RECKPTION IN SPAIN 



Having seen the African party ready 



