Report on the Calculating Machine of M. Scheutz. 541 



College, London. The part constructed contains 19 digits and 3 orders 

 of differences ; and as all the essential movements are comprised in 

 this part, a more extended engine would consist merely of the same 

 members oftener repeated, and would not involve any additional 

 difficulty of construction. It was part of Mr. Babbage's original 

 design that machinery for printing off the results calculated should 

 be included in his engine, and some of the mechanism for this purpose 

 was actually executed. The portion placed in King's College con- 

 tains machinery for calculating only. It does not fall within the 

 province of this report to do more than mention the Analytical 

 Engine subsequently invented by Mr. Babbage, as the machine of 

 M. Scheutz is a Difference Engine, and nothing more. 



A full account of the principles and action of Mr. Babbage's 

 Difference Engine, but without any details of its mechanism, was 

 published in the 'Edinburgh Review' for April to July, 1834. It 

 Avas, as we are informed, the perusal of this paper which induced 

 M. Scheutz to set about the invention of modes of mechanically 

 executing the necessary changes. The result was the completion of 

 the present engine, which has now for some time been in the apart- 

 ments of the Royal Society. In this machine M. Scheutz has 

 followed the general ideas of Mr. Babbage in the distribution of 

 digits and differences, and in particular in throwing back the dif- 

 ferences at every alternate order one stage, from whence results the 

 possibility of acting simultaneously on all the odd and on all the 

 even differences, and thereby making the machine advance one stage 

 by two addition-motions only ; whereas otherwise as many separate 

 addition- motions would have been necessary as there were orders of 

 differences retained. But the mechanism by which the additions 

 and carriages are effected in the machine of M. Scheutz is different 

 from that of Mr. Babbage. The engine is also provided with 

 mechanism for printing, or rather for furnishing stereotype plates of 

 the calculated results. 



As M. Scheutz has taken out a patent for his engine, it will be 

 unnecessary to give a detailed description of the machinery, which 

 may be obtained in the specification, a copy of which has been 

 presented to the Royal Society. It will be sufficient to give an 

 idea of its general construction and extent with a view of estimating 

 its powers. 



The machine takes in the function to be tabulated and the first 

 four orders of differences, each to fifteen digits. Of these only the 

 first eight (in the case of the function itself) are printed, the others 

 being reserved to guard against errors arising from decimal places 

 left out. 



The places of the digits are represented by fifteen vertical spindles, 

 around which, but not usually connected with which, are placed 

 horizontal wheels in five separate tiers. Each wheel has its circum- 

 ference divided into ten equal parts, and is marked with the digits 

 0, 1, 2, 3, 4, 5, 6, 7, 8, 9. In the normal state of the machine the 

 numbers on the wheels of the highest tier represent the function 

 («_,) to be tabulated, and those on the tiers below represent respect- 



