(58 ROUGH WAYS MADE SMOOTH. 



shops, old clocks in buildings where manifestly the flight of 

 time is not much noted, and so forth. Rejecting these from 

 consideration, we find other clocks ranging from one minute 

 or so before our watch time to four minutes or so after it. 

 Before striking a rough average, however, we consider that 

 some among these clocks are placed where it is on the whole 

 better to be a minute or two before the time than a second 

 late, as, for instance, at banks, where there may be 

 occasion to send out clerks so as to make sure of reaching 

 certain places (Clearing-House, General Post-office, and so 

 forth) within specified time limits. On the other hand, we 

 note that others of these clocks are placed where it is 

 better to be a minute or two after time than a second before 

 it, as at railway stations, post-offices, and so on, where it is 

 essential that the public should be allowed time fully up to 

 a specified hour, for some particular service. Taking fair 

 account of such considerations, we might find that most 

 probably the true time lay between half a minute before and 

 two minutes and a half after our watch time. And thus we 

 might infer that in reality the true time was one minute or 

 so later than that shown by our watch. But if we were 

 well acquainted with the characteristics of different clocks 

 along our r oute, we might infer the time (nay, we might to 

 all intents and purposes know the time) far more accurately 

 than this. We might, for instance, pass six or seven shop- 

 windows where first-class specimens of horological work 

 were shown, in eacn window, perhaps, several excellent 

 clocks, with compensated pendulums and other contrivances 

 for securing perfect working. We might find at one of these 

 shops all such clocks showing the same time within two or 

 three seconds ; at the next all such clocks also agreeing 

 inter se within two or three seconds, but perhaps their mean 

 differing from the mean at the last shop of the kind by 

 seven or eight seconds ; and all six or seven shops, while 

 showing similar agreement as regards the clocks severally 

 displayed at each, agreeing also with each other so closely 

 that ten or twelve seconds would cover the entire range 



