106 DR L. BECKER ON THE SOLAR SPECTRUM. 



marked in this way. Most of these lines have been resolved into two or more lines on 

 other occasions. A close double line whose components were not readily separated was 

 marked as a single one with the sign " 3, 1 " affixed. There were also signs for indicating 

 the blackness of an interval between two dark lines, for suspected irregularities in the 

 working of the apparatus, and lastly for recording the interference of clouds. 



The following table gives the number of the series, the day of the month and 

 week, the Greenwich mean time at the beginning and end, and the wave-length to which 

 they belong. These are followed by the number of lines observed and the apparent 

 altitude of the sun at the given times. Further, the table shows the elastic force of 

 water-vapour as computed from Guyot's tables, the pressure of the air (at the observing 

 station), the outside temperature, the degree of transparency of the air ranging from 1 

 equal very transparent to 5 for thick haze, the direction of the wind and its strength 

 rising up to 10 for a gale. Amongst the remarks the intensities of 2 water- vapour lines 

 have been given sometimes, a symbolising the double line, X= 5885*18 A.U., and b 

 X= 5833-24 A.U. 



[Table 



