## Lick Observatory, Mount Hamilton, California

This report covers the period January 1, 1908, to July 1, 1909. It is intended that only the more important items of the activity of the observatory shall be considered, and these quite untechnically.

The total solar eclipse of January 3, 1908, was observed by means of an expedition dispatched from the observatory through the generosity of Honorable William H. Crocker, regent of the University, of California. A popular account of the expedition and its work has already appeared in these _Publications_, and its general features need not be repeated here. In spite of clouds which interfered with carrying out the program during the first third of the total phase, subsequent studies of the photographs showed that the expedition met with an unusual measure of success. 

Dr. Perrine completed his detailed examination of the sixteen photographs, obtained with eight cameras, covering the region 90 by 28o extending in the direction of the Sun’s equator. These photographs had for their purpose the detection of any existing intermercurial planet or planets. In the sudden downpour of rain immediately preceding totality it was not possible to protect everything, and a little water got into these cameras. Some of the photographs are marked by narrow bands where the rain water ran across them. Until after our return to Mount Hamilton it was thought the photographs were damaged to such an extent that the value of the intermercurial search was seriously impaired, and our public announcement embodied this view. It is gratifying to state that these fears were groundless. There are images of more than five hundred stars on the photographs, down to about the ninth magnitude ; and, surprising to relate, the rain-streaked areas contain the images of all the known stars we expected to find thereon. All the images have been identified as those of well-known stars. In our opinion, the work of the three Crocker Expeditions, to observe the eclipses of 1901, 1905, and 1908, brings the observational side of the intermercurial planet problem---famous for half a century---definitely to a close. It is not contended that no planets will be found in the intermercurial region : it would not be especially surprising nor in contra- diction to beliefs here expressed if small planets should be discovered at some future time; but it is confidently believed that their mass would be inadequate to account for the observed disturbances in the motion of Mercury.