676 TRANSACTIONS OF THE AMERICAN INSTITUTE. 



to Albany, he visited the Dudley Observatory, under the direction of Prof. 

 G. W. Hough. He examined there the following instruments: 



1st. The Olcott Meridian Circle, made by Pistor and Martins, Berlin- 

 Object glass 8 inches; Focal length 19 feet. 



2d. The Transit Instrument by the same makers. 



3d. The Equatorial Refractor, made by the late Henry Fitz, of New York. 

 Object glass 13 inches; Focal length 15 feet. 



4th. The Comet Seeker, made by Mr. Alvin. Clark, of Boston. 



5th. The Declinometer, invented by the late Prof. Mitchel, and made by 

 Messrs. Foster and Twitchell, of Cincinnati. 



6th. The Charting Machine, made by Mr. Fasoldt, of Albany. 



1th. The Sidereal Clock, No. 1, movement by Dent, pendulum applied by 

 Bond and Son, of Boston. 



8th. Sidereal Clock, No. 2, by Howard and Company, of Boston, 



9th. Chronograph, invented by Professor Mitchel, made by Foster and 

 Twitchell, Cincinnati. 



10th. Barometer, by Fastre of Paris. 



Also a magnetic Mean Time Clock, by Mr. Farmer, of Boston; Chronome- 

 ter, by Johnson, of London; Clocks for the Observing Rooms, and other 

 minor apparatus needed or useful in an observatory. 



The speaker was most interested in the Calculating Machine of Scheutz, 

 first exliibited at the International Exhibition in London. The following 

 description of it is from the pen of Prof Hough: 



The Savedish Tabulating Machine of Mr. George Scheutz. 



It is a well known fact that Mr. Charles E. Babbage was the first to 

 attempt the construction of a Difference Engine; but owing to some misun- 

 derstanding between the Inventor and the English Government, under 

 whose patronage the v.'ork was carried on, it was never completed. 



About the year 1834 or 1836, Mr. Scheutz, a printer at Stockholm, heard 

 of Mr. Babbage's Machine, and at once conceived the idea of building one 

 himself 



The present machine, which bears the impression "Stockholm, 1853," is 

 the product of his labors, continued with unwearied diligence and at great 

 pecuniary sacrifice through nearly twenty years. It is the only one ever 

 perfected, and although based on the same mathematical theory, is yet 

 essentially dilferent in its mechUnism from that contemplated by Mr. Bab- 

 bage. It was purchased for this observatoiy in 1858, and was put in opera- 

 tion for a short time in 1858. 



It was found to be in a very disordered condition, and the greater part 

 of the labor expended upon it was required by adjustments and repairs. 

 Of the details of its mechanism, no satisfactory conception can be given 

 without illustrations, and without more space than can here be afforded. 



It possesses a twofold power, with mechanism appropriate for each; not 

 necessarily connected, though simultaneous and automatic in its entire 

 action. These functions are, first, the production of certain numerical 

 results; second, the conversion of these results into a permanent legible 

 record. 



The theory of the machine is based on the mathematical truth that in 



