86 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1918. 



were materially increased by the choice of one so far east as Kansas. 

 Magnetic observers sent out by Dr. Bauer were also at Lakin, and, 

 being already on the ground, aided materially in establishing Mr. 

 Aldrich's party. 



The observers chose the site on Monday, June 3, and were hospitably 

 entertained at the home of Mr. Pittenger, a rancher. The cameras 

 were set up in a barn looking out westward through a slot cut away 

 for the purpose. Unfortunately cloudy and rainy weather hindered 

 the preparations and prevented the rating of the clock and the photo- 

 graphic focusing of the lenses on the stars, so that the adjustment 

 could be made but roughly. 



On eclipse day, Saturday, June 8, no hope was felt of fair weather 

 during the forenoon, but fortunately the sky became nearly free from 

 clouds about 1 o'clock and continued so until after nightfall and dur- 

 ing Sunday. All times of contact were observed by Rev. Fr. Wood- 

 man, who also exposed the cameras, as follows : 



Latitude 37° 53' 04.2" N. 



Longitude 101 17 51.3 W. 



Contacts (Greenwich mean time) : 



//. m. s. 



First - 10 19 48. 5 



Second 11 27 15. 1 



Third 11 2S 37.3 



Fourth 12 29 45. 4 



The observers regarded the eclipse as unexpectedly dark and the 

 phenomenon as more than usually grand. 



Very good photographs of the corona were obtained, showing ex- 

 tensions to about 3 diameters of the sun in some directions. Owing 

 to lack of opportunity to rate the clock there was some evidence of 

 imperfect following. The negatives were developed, with the kind 

 permission and advice of Director E. C. Pickering, by Mr. King at 

 Harvard College Observatory. 



Messrs. Aldrich and Kramer observed successfully throughout the 

 afternoons and early night hours of June 8 and June 9 with the 

 pyranometer. The results obtained measure the gradual diminution 

 of the radiation of the sun and of the brightness of the sky as the 

 eclipse progressed, the outgoing radiation from the earth's surface 

 during totality, the gradual increase of sun and sky radiation after- 

 wards, their decline toward sunset, and the outgoing radiation from 

 the earth's surface after nightfall. Numerical values will be pub- 

 lished later. 



WORK AT MOUNT WILSON. 



Mr. L. B. Aldrich occupied the Mount Wilson station until Octo- 

 ber 11, 1917, and again after June l4, 1918. He continued the usual 

 solar constant determinations and the determinations of the distribu- 

 tion of radiation over the sun's disk. Two improvements were intro- 

 duced in the apparatus. 



