182G.] linnk Forj^cry. 517 



satisfled with llic experiment ? We have the fullcfst evidence of the direct 

 contrary. The country hanks are scarcely ever forged on. This Sir M, W. 

 Ridiey, in Iiis sa.^acity, attributed to the signature of tlie firms l)einjj so well 

 known in their districts that forgery would be detected ! But what is easier 

 tiiaii the imitation of hand-writing? or what is less keen on the subject tlian 

 the eye of a ploughman ? Mr. Peel answered this at once by saying, "that 

 the National Bank-notes of Ireland are very rarclij forged, though they circu- 

 late in parts of the country where the written siLMiaturcsare no more known, 

 than if they were written by the man in the moon." 



Yet, let any one compare the English country bank-paper, or the Irish, with 

 that of almost any of the artists who have sent in their inventions — with Per- 

 kins's note, for instance — ^he will see at once, that if the former are found to pre- 

 vent forgery in a great degree, the latter woultl be praclicalh/ inimituhlc by the 

 forger, without instant hazard of detection. Steam-engines and ponderous 

 machinery cannot work in a corner. First-rate engravers are actually among 

 the rarest of all artists ; they are proportionably paitl : and the man who 

 receives from five hundred to filteen hunilred guineas for a plate, will not be 

 likely to run his neck into the halter, at the discretion of the miserable agent in 

 whom he must necessarily confide to pass the note. 



But there is one important recollection lurking at the bottom of all this 

 indolence. We shall not dwell upon it now. But if the Bank were compellable 

 to give caah for every note, that, upon a fair com|)arison with tljcir present 

 clumsy fabrication, would deceive the eye of a jury; we should not belong 

 without some ettbrt to improve the bank patier. We should rejoice to see 

 such a law enforced : in a week we should have a note that, to all practical 

 purposes, would defy imitation. 



ON MECHANICAL NOTATION. 

 By C'las. Balbcip,c, Esq., F.li.S., ahstracled from a Paper read at the Rot/al Sucicty, 



March loih 1&2(). 



In the construction of an engine for calculating and printing mathematical 

 tables, in which the author of this paper has been for some time occupied, he 

 has met with considerable difficulty from the want of any method by wliich all 

 those motions which take place in-every machine at the same instant may be 

 easily preserved and referred to, and by which the movement of any part might 

 instantly be traced back through all the intervening stages up to the first mover 

 of the machinery. The usual modes of mechanical drawing were quite insuf- 

 ficient for these purposes, except in machines of the simplest construction ; and 

 even if they had not altogether failed in more complicated cases, the time and 

 expense required for their execution would have effectuallj' prevented their 

 eniploj'ment. 



The most important question was to contrive some method by which 

 all the simultaneous movements occurring at any moment should be at once 

 visible ; and the history of the state of motion or rest of any given part, 

 should be apparent during the whole cycle of the action of the engine. 



The author had recourse to a system of signs, which in some manner re- 

 semble those employed in algebra, while they difier from them by having a 

 general resemblance to the things they were intended to represent. Having 

 gradually found that this system, which he calls " Mechanical Notation," was 

 readily susceptible of affording other information than that for which it was at 

 first contrived, he gave to it additional extension: and in its present form it 

 gives, almost at a glance of the eye, information relative to any of the following 

 points (the name of every part of any engine being written at the top of the 

 paper): 



1. Its representations in all the drawings will be pointed out. 



2. The number of teeth in any wheel, pinion, or sector will be seen. 



3. The actual angular velocity ofevery moving part will be seen. 



4. The mean angular velocity will also appear. 



5. The origin of the motion of each part will be seen, and thus the cause of 

 its motion v/ill be traced up to the first mover. 



