On RrrHMICAL MEASURES. 83 



attended to by the mind, are conceived as feeble. As five is too 

 large a number to be comprehended by one individual a6l of 

 the mind, we can only form parcels of that number, by count- 

 ing off two pairs, confidering the fifth fingle found as feeble, 

 and fixing our attention upon the fixth, as the leading found of 

 the next pair ; or by counting off twos and threes, or threes and 

 twos alternately. This infertion of the fingle time, at the end 

 of every two pairs, changes the order of the ftrong and feeble 

 founds, in every fucceeding parcel. Although this operation is 

 pradicable, it is probably very feldom adually performed. The 

 frequent and fudden changes of the arrangement of ftrong and 

 feeble founds, require an uneafy effort of attention in the per- 

 former, and give an unpleafing fiirprife and difappointment to 

 the hearer. Both feel a ftrong defire to have the number of fix 

 times completed, either by a lengthened found, or by a filence. 

 Laftly, we have the farther power and difpofition to join toge- 

 ther two,' three or four of our firft parcels, thus forming larger 

 combinations. 



By means then of the powers now defcribed, we are enabled 

 to exprefs a fucceffion of founds whofe durations may be very 

 different, but may, at the fame time, be moft accurately related 

 to one another, according to certain proportions. We are alfo 

 enabled, upon hearing fuch a fucceffion of founds, with readi- 

 nefs and eafe, to feel the proportional duration of each, provi- 

 ded the fimple proportions above mentioned be conftantly ob- 

 ferved. In order to this, we firft of all fix our attention upon 

 fome determined duration, which may be fomething near to 

 the intervals obferved in walking, or in fome other of the uni- 

 form motions with which we are familiar. This duration we 

 confider as an unit of time. Having eftablifhed this, we can 

 exprefs any number of them with great uniformity ; we can 

 divide fome of them as we go along into parts, or combine two 

 or more of them into lengthened foxmds. By habit, we can 

 take our unit, at different times, greater or fmaller^ we can 



L 2 make 



