78 N. F. DUPUIS ON A MECHANICAL MEANS, Erc. 
absolute, now takes place, and m again moves along with s for another 30m., and so on 
continually. Thus, supposing s to revolve exactly in one sidereal hour, m will never be 
more than about 44 seconds astray, and then only at two particular periods in the hour. 
This is two small a quantity to be read from the minute hand of any clock. 
If the arrangement were attached to the seconds-hand arbor, which is quite practicable, 
as no wheel contains more than 99 teeth, and on account of the slowness of the motion the 
wheels might be made very light, the mean-time seconds could never be in error more 
than 4 second, and this proportionately large error arises from the fact that, from the very 
nature of a clock, it goes by jumps instead of uniformly. 
