Many torches, of course, are required, as the signal for each letter is a double one.
But if all is properly prepared for the purpose, what is required can be done whichever system we follow.,
Those engaged in the work must have had proper practice, so that when it comes to putting it in action they may communicate with each other without the possibility of a mistake.
From many instances it is easy for all who wish it to learn how great the difference is between the same thing when it is first heard and when it has become a matter of habit.
For many things which appear at the beginning to be not only difficult but impossible are performed quite easily after time and practice.
There are many other examples which confirm this, but the clearest of all is the case of reading.
Here if we put side by side a man who is ignorant and unpractised in letters, but generally intelligent, and a boy who is accustomed to read, give the boy a book and order him to read it,
the man will plainly not be able to believe that a reader must first of all pay attention to the form of each letter, then to its sound-value, next to the combinations of the different letters, each of which things requires a considerable amount of time.
So when he sees that the boy without hesitation reels off five or seven lines in a breath he will not find it easy to believe that he never read the book before,
and he will absolutely refuse to believe this if the reader should be able to observe the action, the pauses, and the rough and smooth breathings.
We should not, therefore, abandon, anything useful owing to the difficulties which show themselves at the outset, but we must call in the aid of habit, through which all good things fall into the hands of men, and more specially when the matter is one on which our preservation mainly depends.
In offering these observations I am acting up to the promise I originally made at the outset of this work. For I stated that in our time all arts and sciences have so much advanced the knowledge of most of them may be said to have been reduced to a system.
This is, then, one of the most useful parts of a history properly written.
Walbank Commentary