REPORT OF THE PRESIDENT, 1914. 29 



The work of the Observatory for the year is much too extensive 

 to permit of adequate summary here. But this is unnecessary, 

 since the Director's report, in addition to detailed accounts 

 of observations, investigations, and construction, gives a con- 

 densed abstract of the sahent results arrived at. These results 

 are briefly and clearly stated in 59 paragraphs. They refer to 

 correspondingly numerous measurements, calculations, and in- 

 ductions made in studies of the sun and other stellar bodies whose 

 characteristic properties are now stimulating extraordinary 

 advances in cosmic physics. 



Progress in construction of the 100-inch telescope has been 

 made as rapidly as could be expected in so formidable an under- 

 taking. The delicate optical task of shaping the 100-inch mirror 

 has been brought successfully by Mr. Ritchey to the stage of 

 sphericity which precedes the final state of parabolization. The 

 difficulties due to distortion of the mass of the disk, referred 

 to in previous reports, have been overcome and other obstacles 

 due to temperature inequalities in the optical room are likewise 

 yielding to appropriate precautions. In the meantime the 

 foundations for this telescope have been completed and the 

 mounting and dome are expected to be ready for erection during 

 the coming year. Several smaller parts and accessories for this 

 instrument, requiring special exactness, are under construction 

 at the shops of the Observatory in Pasadena. Many additions 

 and improvements in the apparatus already installed at the 

 Observatory have been made. The 60-foot tower telescope par- 

 ticularly, which was originally cheaply constructed in order to 

 test the possible advantages of such a departure from earlier 

 forms of telescopes, has been put in a state of efficiency compar- 

 able with that of the 150-foot tower telescope, leaving the latter 

 free for the uses to which it is specially devoted. In these general 

 improvements much attention has been given to rendering the 

 plant on Mount Wilson more nearly fire-proof. The mountain 

 road has been repaired, widened, and strengthened in many parts 

 in anticipation of the heavy traffic essential to transportation of 

 the 100-inch telescope to its destination. 



