At the last session of the Congress of the UnitedStates of America, an appropriation of £6,000 was made for the observation of the Total Eclipse of the Sun, under the direction of Professor Benjamin Peirce, the Superintendent of the U.S. CoastSurvey. This generous act of legislation was suggested by one of the ablest statesmen of America, the Hon. John A. Bingham, of Ohio, and passed both houses unanimously.
An officer was immediately sent to examine the various places, and obtain all the local information which might be required to select the most favourable positions for observation. The expedition has been divided into two parties, each of which consists of about twelve persons. One party is under the immediate direction of Professor Peirce, and will observe in Sicily; and the other is under the direction of Professor Winlock, the director of the Observatory of Harvard University, and will observe in Spain. Almost all the astronomers of the expedition were upon the central path of the great eclipse which occurred in America in August, 1869, so that they have already been under fire, and are prepared for the sudden outburst of the total obscuration.The observations for precision will be entrusted in each party to an experienced officer of the survey,who will be upon the ground at least a fortnight before the eclipse. He will have the instruments all properly mounted and protected, the time well observed, and the arrangements made so that the principal observers of the physical phenomena may find everything in readiness when they arrive. Their presence will not, therefore, be required till within a few days of the eclipse. The officers upon whom this duty has devolved are Mr. Schott and Mr. Dean, assistants of the Coast Survey.
The spectroscopic observations have been chiefly arranged by Professor Winlock, assisted by Professors Young and Morton. New and peculiar methods have been prepared for preserving a record of the lines of the spectrum for subsequent measurement and discussion.The photographic preparations are varied and original. The party of Professor Peirce will have photographic apparatus prepared by Mr. Rutherford of New York, with lenses especially ground for the purpose under his direction by Fitz of New York, and young Fitz will himself superintend this portion of the observations. The party of Professor Winlock will have its photographic apparatus prepared, under the directions of the Professor, by Clarke of Cambridge, and will use lenses ground by Clarks. Alvan Clarke, jun., will also assist in these observations. Professor Winlock’s new method of photographing the sun through a long tube will be used in a portion of this class of observations. In both parties arrangements are made for long and short exposures in different instruments during the period of totality.
The polariscopic observations will be made by Professor Pickering in the party of Professor Winlock.
General observations of the corona will be made by as many of the party as possible, and it is hoped that Steinheil‘s hand comet-seekers will be especially available for this class of observation. Hand spectroscopes will also be used by several of the party, and it is hoped that in the preparations for this portion of the service material assistance will be denied from Mr. Lockyer’s suggestions.
It is worthy of notice that two of the ablest officers or Engineers of the United States’ Army have been detailed by the War Department to accompany the Expidition. They are Major Abbott, whose name is familiar to hydraulic engineers through his connection with General Humphrey’s Monograph upon the Mississippi river, and Captain Emil. –
The mechanics Magazine, 1870