8: Measurement

Another advantage of machinery is in the accuracy of its measurement, which protects against "the inattention, the idleness, or the dishonesty of human agents." In business, accurate measurement is critical to maintaining profitability, but measuring things and keeping count is one of the most wearisome occupations of the human mind.

He mentions the simple pedometer, which counts the number of steps a person has taken as a means of measuring distance. It is exceedingly difficult for a human being to keep count of something so trivial as the number of steps taken along a route from one place to another, and because of differences in gait, one person's "step" is different to another's. The pedometer measures distances with accuracy and reliability that a human could not achieve.

Next, he mentions ways in which devices help to maintain the accuracy and performance of human workers. Watchmen, who are infamously delinquent in making their rounds, can be regulated by the use of time-clocks situated along his route, requiring him to pull a cord once an hour, and informs his employer whether he has actually made his rounds during the night. Or consider the use of a stop-cock in bartending, which permits only a certain measure of fluid to be dispensed - ensuring the patron receives no more and no less than he has purchased.

(EN: As usual, this goes on for a while, mentioning the specific function of various measuring devices in gratuitous detail.)

Measuring devices can observe phenomena too minute to be perceptible to human senses, or to gradual to be appreciated. For example, the motion of stars and planets can be mapped over months and years by a device, or to the other extreme can precisely measure fractions of a second.

There's also a mention of alarms, which provide a signal when some condition has occurred. It is particularly tedious and wasteful for a person to be hired to pay constant attention to something that does not change except once in a great while - and the likelihood a person hired to do such work will become inattentive and fail to promptly notice when anything occurs.