Observatory News.

The members of the expedition to the new Harvard astronomical station, at Arequipa, Peru, arrived at their destination about a week ago and Professor Pickering of the observatory is daily expecting news from them. The latest letters from them were mailed at Panama. Mr, W. H. Pickering, a brother of Professor Pickering, is in charge of the expedition. It is expected that many important discoveries will accrue to science from the work which has just been begun at this mountain city of Peru.

Arequipa, the site of the observations, is situated on the Mollendo railway, at an elevation of about eight thousand feet, and is the second largest city in Peru. It is here that all their principal instruments are located. A railroad leads from this city up into the Andes, six thousand feet higher, so that when special observations are essential, recourse is had to the latter place and hither most of the instruments may be conveyed, although the larger telescope is never moved from Arequipa. Investigations made here are, conducted with regard-first to the meteorology of the globe, with particular reference to cloudiness and other phenomena affecting the choice of astronomical stations; secondly, to to the fundamental principles of astronomical photography; thirdly, to the great nebulous region comprising a large part of the constellation Orion; fourthly, to the best form of standard light; and finally to other details of quantitative photometric work.

"Arequipa," said Professor Pickering, "affords specially good opportunities for meteorological work. In Europe there are less chances for such thorough investigations."