VOL. XLIV.] PHILOSOPHICAL TRANSACTIONS. 333 



The first line, being 2 inches, represents a semibreve. 

 The second is 1 inch, and denotes a minim. 

 The third is half an inch, and signifies a crotchet. 

 The fourth is a quarter, and answers to a quaver. 

 The fifth is an eighth, and denotes a semiquaver. 



Maxim 3. — ^The quantity of the blank intervals, or discontinuity of the lines, 

 will exactly represent the duration of silence or rests. Ex. gr. 



, — = ^ r T 



' =}i\\n 



Maxim 4. — ^The different degrees of musical sounds, as gamut, a re, b mi, 

 &c. may be represented by the different situations of those black lines on the red 

 ones or faint ones. See fig. 6, pi. 7- 

 Problem. — To make a Machine to JVrile Music in the aforesaid Character, as 



fast as it can be Played on the Organ or Harpsichord, to which the Machine 



is fixed. 



Suppose that a cylinder may be made by the application of a circulating, not 

 a vibrating pendulum, to move equally on its axis the quantity of 1 inch in a 

 second of time, which is about the duration of a minim in allegros. As the cy- 

 linder a, fig. 7, and to move under the keys of an organ, as b, c, d, and nail 

 points under the heads of the keys ; it is manifest that if an organist play a minim 

 on c, that is, if he press down c for the space of a second, the nail will make a 

 scratch on the cylinder of 1 inch in length, which is the mark for a minim. 



Again, if he rest a crotchet, that is, if he cease playing for the space of half a 

 second, the cylinder will have moved under the nails half an inch without any 

 scratch ; but if the organist next press down d for the space of half a second, the 

 nail under d will make a scratch on the cylinder half an inch long, which is the 

 mark for a crotchet. It will likewise be differently situated from the scratch that 

 was made by c, and consequently distinguished from it as much as the notes now 

 in use are from each other by their different situation in the lines, in fig. 6. 

 These 3 instances include all that can be performed on an organ, &c. . 



Therefore it is already demonstrated, that whatever is played on the organ 

 during one revolution of the cylinder a (fig. ^), will be inscribed on it in intelli- 

 gible characters. He proceeds to show how this operation may be continued for 

 a long time. 



In fig. 8, aa, b, c, d, are the same as in fig. 7. Let x be a long scroll of paper 

 wound about such a cylinder as z. Let eeee be the same scroll brought over the 

 cylinder aa, to be wound on the cylinder yy, as fast as the motion of aa, which 

 is determined by a pendulum, will permit. It is manifest, that whatever is played 



