LEANDER McCORMICK OBSERVA TORY. The Leander McCormick Observa tory of the University of Virginia owes its origin to the generosity of the late Leander J. McCormick of Chicago. The chief instrument is the 26-inch refractor, both lens and mount ing the work of Alvan Clark and Sons. The lens when finished was the largest in the world and it was regarded by Alvan G. Clark to be his masterpiece. While testing it, before its erection at the University of Virgina, the star * Cygni was discovered to be a double. The observatory was opened in 1882. The first di rector was Ormond Stone. The work under his direction was entirely visual and investiga tions were carried out along the following lines: A study of the Orion nebula, a search for southern nebula, micrometer measures of double stars, satellites and comets, photometric work by means of a wedge and observations of long period variables by the Argelander method. S. A. Mitchell succeeded Professor Stone in 1913. A double-slide plate holder was attached to the eye end of the telescope and photographic work was undertaken, using a color filter and isochromatic plates. The chief work at present is the determination of the parallaxes of the fixed stars by means of pho tography. The parallaxes of 125 stars were found as the result of two and a half years' work. Photographic work is also done by placing a wire grating in front of the objec tive. This work is for the purpose of deter
mining the photovisual magnitudes of the Har vard standard regions and is being carried on in co-operation with Harvard College Observa tory. The McCormick Observatory is the head quarters of the American Meteor Society. In 1916 more than 10,000 observations on meteors or shooting stars were made in the United States and Canada, and largely by amateur as tronomers. These observations are sent to the McCormick Observatory and are discussed by Dr. Charles P. Olivier and the results pub lished. The work on long period variables has been continued. On accotmt of the large aper ture (26-inch) stars are visible near their min ima and when they are invisible to the tele scope at Harvard and to the smaller telescopes used by the American Association of Variable Star Observers: Micrometer work on doubles, etc., has likewise been continued. There are three felloWships available for graduate stu dents who wish to continue work for the de gree of doctor of philosophy. The income of the observatory is derived from appropriations by the University of Virginia, by gifts from the Leander McCormick estate and from Mr. Edward D. Adams.of New York and by small grants from the National Academy of Sci ences for meteor research.