330 
POPULAR SCIENCE REVIEW. 
manufacture, especially amongst metals, wliicli does not 
continually involve scientific knowledge. 
Not only lias science benefited manufacturers, but also 
operatives, because tlie extension of science to manufacturing 
purposes bas compelled them to make themselves acquainted 
with intellectual subjects. Instead of remaining mere machines, 
mechanically performing the work set before them, they are 
obliged to exercise the faculties of observation and judgment 
in watching 1 the results and directing the action of mechanical, 
physical, and chemical forces. Instead of following the blind 
path of experience, using unknown forces to accomplish some 
definite result, they pursue their labours with the aid of known 
and certain laws. 
No man has more occasion to bless the introduction of the 
steam-engine, machinery, the galvanic battery, and science in 
general, than the working mechanic, because it has mitigated 
his physical toil by giving him the duty of simply directing the 
labour instead of actually performing it : whilst it has deprived 
him of one kind of employment it has provided him with some- 
thing better. But a few years ago the operatives in the silver- 
plating trade had to lay the silver on the articles with their 
hands and the aid of a soldering-iron; now, they have simply 
to set their batteries in action, and watch the electricity doing 
it for them. In a similar manner the working engineer at his 
metal-turning lathe has merely to direct the action of his tools 
whilst the steam-engine performs the heavy labour of turning. 
In the present period of scientific progress, when the 
attention of men of business is so frequently attracted to 
some new invention or discovery which appears likely, if not 
to supersede their particular occupation, at least to have some 
influence upon it, it is the interest of every such person to 
watch the progress of science and to seize it for his own 
advantage, instead of allowing others to do so, and thereby 
divert his trade into other channels. 
No art nor manufacture is so perfect as to be exempt from the 
influence of discoveries and inventions, and no man can pro- 
duce so perfect an article, but that by the aid of science a 
better may be produced. 
In what consists the great success of applying science to 
trade? — simply the influence of demonstrable truth. We know 
that if we have once discovered all the laws or conditions of 
some improved process or result in a manufacture, the repro- 
duction of exactly the same conditions will hereafter enable us 
to invariably produce the same result. In this respect science 
differs from empiricism, for in empirically working a process 
we are ignorant of the condition or laws which are operating, 
whilst with a scientific knowledge we understand those laws. 
