REPORT OF THE PRESIDENT, I909. 35 



which demonstrate the high efficiency of the 60-inch equatorial telescope, and 

 many other interesting details concerning the progress of his department of 

 work; to all of which the attention of the Trustees is respectfully invited. 

 It may suffice here, therefore, to record only one other item of interest, 

 namely, the failure thus far of the manufacturers of glass at St. Gobain, 

 France, to furnish a satisfactory disk for the 100-inch Hooker telescope. 

 The disk reported as en route for delivery a year ago proved so defective that 

 it had to be rejected. The distinguisht manufacturers are still confident, 

 however, that they can meet the requirements, and it is hoped that thru the 

 collaboration of Professor Ritchey, of the Observatory staff, who has spent 

 some months at St. Gobain during the year, a satisfactory disk may be ulti- 

 mately secured. 



The most important event of the year in connection with this department 

 is the construction, equipment, and putting into commission of the non- 

 j^ , magnetic ship, registerd as the yacht Carnegie. A con- 



Terrestrial tract for the construction of this ship was let on December 



Magnetism. ^^ j^^g^ ^^ ^^^ ^^^^ Yacht Basin Company, of Brooklyn, 



N. Y. She was launcht on June 12, 1909, and set sail on her trial voyage 

 August 21, 1909. She is primarily a sailing craft of brigantine rig, but is 

 provided also with auxiliary propulsion by means of an internal-combustion 

 engine for which gas is supplied by a producer which will generate gas from 

 coal, lignite, or wood. 



The Carnegie sailed first to Gardiner's Bay, Long Island, thence to St. 

 Johns, Newfoundland, thence to St. Johns, Newfoundland, and thence to 

 Falmouth, England. She will continue magnetic surveys of the Atlantic 

 until about the first of February, 1910, when she will return to Brooklyn to 

 have copper sheathing applied to her hull. 



Altho it is now too early to report adequately with respect to the perform- 

 ance of this unique ship, it may be said that she is highly satisfactory in all 

 essential particulars. She proves to be so nearly non-magnetic that correc- 

 tions for her magnetism are of the same order as the errors of observation 

 to which magnetic determinations are subject. In this fundamental prop- 

 erty she quite outclasses the yacht Galilee, charterd during 1905 to 1908 for 

 magnetic surveys of the Pacific Ocean. It may be stated also that in her 

 first voyage across the Atlantic errors of prime importance to navigation 

 were found in the best magnetic charts now used by mariners. 



It is a source of pleasure to record the fine scientific spirit of cooperation 

 shown by all parties connected with the design, construction, and use of this 

 vessel. The Institution is especially indebted to the high professional skill 

 and fidelity of Mr. Henry Gielow, architect and superintendent, and to Mr. 



