FARMERS' REGISTER-CALCULATING MACHINE. 



241 



transferred to types bj^ the common process. The I required, or any succession of terms commencing 

 ijreaterpartof the calculalims; machinery is.already at a distant point 



constructed, and exhil)its workmanship of such 

 extraordinary sldll and beauty that nothing ap- 

 proaching to it lias been witnessed. In order to 

 execute it, particularly those parts of the apparatus 

 which are dissimilar to any used in ordinary me- 

 chanical constructions, tools and machinery of 

 great expense and complexity have been invented 

 and constructed; arid in many instances contri- 

 vances of singular ingenuity have been resorted 

 to, which cannot fail to prove extensively usetul in 

 various branches of tlie mechanical arts. 



The drawings of tills machinery, which form a 

 large part of the work, and on which all the con- 

 trivance has been bestowed, and all the alterations 

 made, cover upwards of 400 square feet of surface, 

 and are executed with extraordinary care and pre- 

 cision. 



In so complex a piece of mechanism, in which 

 interrupted motions are propagated simultaneously 

 along a great variety of trains of mechanism, it 

 might have been supposed that obstructions would 

 arise, or even incompatibilities occur, from the im- 

 practicability of tbreseeing all the possible combi- 

 nations of the parts; but tliis doubt has been en- 

 tirely removed by the constant employment of a 

 s}-stem of mechanical notation invented bj Mr. 

 Babbage, which places distinctly in view, at ever)' 

 instant, the progress of motion through all the 

 pa:rts of this or any other machine, and by writing 

 down in tables the times required for all the move- 

 ments, this method renders it easy to avoid all risk 

 of two opposite actions arriving at the same in- 

 stant at any part of the engine. 



In the printing part of the machine less progress 

 has been made in the actual execution than in the 

 calculating part. The cause of this is the gi-eater 

 ditficulty of its contrivance, not for transferring the 

 computations from the calculating part to the cop- 

 per or other plate destined- to receive it, but for 

 giving to the platfe itself that number and variety 

 of movements which the forms adopted in printed 

 tables may call for in practice. 



The practical object of the calculating engine is 

 to. compute and print a great variety and extent of 

 astronomical and. navigation tables, which could 

 not be done without enormous intellectual and 

 manual labor, and wIiIqIi, even if executed by such 

 labor, could not be calculated with the requisite 

 accuracy. Mathematicians, astronomers, and 

 navigators do not require to be informed of the real 

 value of such tables; but it may be proper to state, 

 for the information of others, that 17 large folio 

 volumes of lon;arithmic tables alone were calcu- 



Bcside the cheapness and celerity with which 

 this machine will perlbrm its work, the absolute 

 accuracy of the printed results deserves especial 

 notice. By peculiar contrivances, any small error 

 produced by accidental dust, or by any slight inac- 

 curacy in one of the wheels, is corrected as soon, as 

 it is transmitted to the next, and this is done in 

 such a manner as effectually to prevent any accu- 

 mulation of small errors i'wm producing an errone- 

 ous figure in the result. 



In order to convey some idea of this stupend- 

 ous undertaking, we may mention the effects pro- 

 duced by a small trial engine constructed by the 

 inventor, andb}' which he computed the following 

 table ti-om the formula x2 by xby 41. The figures, 

 as they were calculated by the machine, Avere not 

 exhibited to the e3'e as in sliding rules and similar 

 instruments, but were actually presented to the 

 eye on two opposite sides of the machine, the 

 Tiumber 383, for example, appearing in figures be- 

 fore the person employed in copying. 



Tabic calculated by a small trial engine. 



While the machine was occupied in calculating 

 this table, a friend of the inventor undertook to 

 write down the numbers as they appeared. In 

 consequence of the copyist writing quickly, he 

 rather more than kept pa,ce with the engine, but 

 as soon as five figures appeared, the machine was 

 at least equal in speed to the writer. At another 

 trial 32 numbers of the same table were calculated 

 in the space of 2 minutes and 30 seconds, and as 

 these contained 82 figures, the engine produced 33 

 figures every minute, or more than one figure in 

 every two seconds. On another occasion it pro- 

 duced 44 figures per minute. This rate of com- 

 putation could be maintained for any length of 

 time: and it is probable that tew writers are able to 

 copy with equal speed for many hours together. 



Some of that cla,ss of individuals who envy all 

 great men, and deny all great inventions, have 

 ignorantly stated that Mr. Babbage's invention is 

 not new. ' The same persons, had it suited their 

 purpose, would have maintained that the invention 



iated at an enormous expense by the French go- of spectacles was an antici[)ation of the telescope; 

 vernment; and that the British government re- but even this is more true than the allegation that: 

 garded these tables to be of such national value the arithmetical machines of Pascal and othera 

 that they proposed to the French Board of Lon- ^rgj-e the types of Mv. Babbage's engine. The 

 ntude, to print an abridgement of them at the object of these machines was entirely different. 



joint expense of the two nations, and offered to 

 advance £5,000 for that purpose. Besides loga- 

 rithmic tables, Mr. Babbage's machine will calcu- 

 late tables of the powers and products of numbers, 

 and all astronomical tables for determining the po- 

 sition of the sun, moon, and planets; and the same 

 mechanical principles have enabled him to inte- 

 grate enumerable equations of finite differences, 

 — that is, when the equation of difference is given, 

 he can, by setting an engine, produce at the end 



Their highest functions were to perform the opera- 

 tions of common arithmetic. Mr. Babbage's en- 

 gine, it is true, can perform these oi)erations also, 

 and can extract the roots of numbers, and approx- 

 imate to the roots of equations, and even to their 

 impossible roots. But this is not its object. Its 

 function, in contradistinction to that of all other 

 contrivances for calculating, is to embody in ma- 

 chinery the method of differences, which has never 

 before been done; and the effects which it is capa- 



of a given time any distant term which may be i ble of producing, and the worka which in the 

 Vol. II.— 20 



