[45.] Now this method, though introducing a certain improvement in the system of fire signalling,The drawbacks to this method. is still wanting in definiteness: for it is evident that it is neither possible to anticipate, or, if you could anticipate, to write upon the rod every possible thing that may happen: and therefore, when anything unexpected in the chapter of accidents does occur, it is plainly impossible to communicate it by this method. Besides, even such statements as are written on the rods are quite indefinite; for the number of cavalry or infantry that have come, or the particular point in the territory which they have entered, the number of ships, or the amount of corn, cannot be expressed. For what cannot be known before it happens cannot have an arrangement made for expressing it. And this is the important point. For how is one to take proper measures for relief without knowing the number or direction of the enemy? Or how can the party to be relieved feel confidence or the reverse, or indeed have any conception at all of the situation, if it does not know how many ships or how much corn have been despatched by the allies?
But the last method which was hit upon by Cleoxenus and Democlitus, and further elaborated by myself,The improved method of Cleoxenus and Democlitus. is above all things definite, and made capable of indicating clearly whatever is needed at the moment; but in its working it requires attention and more than ordinarily close observation. It is as follows: Divide the alphabet into five groups of five letters each (of course the last group will be one letter short, but this will not interfere with the working of the system). The parties about to signal to each other must then prepare five tablets each, on which the several groups of letters must be written. They must then agree that the party signalling shall first raise two torches, and wait until the other raises two also. The object of this is to let each other know that they are attending. These torches having been lowered, the signalling party raises first torches on the left to indicate which of the tablets he means: for instance, one if he means the first, two if he means the second, and so on. He next raises torches on the right showing in a similar manner by their number which of the letters in the tablet he wishes to indicate to the recipient.
[46.] This matter being agreed upon, the two parties must go to their respective points of observation; and each must have, to begin with, a stenoscope with two funnels, to enable him to distinguish through one the right, through the other the left position of the signaller opposite him. Near this stenoscope the tablets must be fixed, and both points, to the right and to the left, must be defended by a fence ten feet long and about the height of a man, in order to make it clear on which side the torches are raised, and to hide them entirely when they are lowered. These preparations completed on both sides, when a man wishes, for instance, to send the message “Some of our soldiers to the number of a hundred have deserted to the enemy,”—the first thing to do is to select words that may give the same information with the fewest letters, for instance, “A hundred Cretans have deserted,” for thus the number of letters is diminished by more than a half and the same information is given. This sentence having been written on a tablet will be transmitted by five signals thus: The first letter is κ, this comes in the second group of letters and therefore on the second tablet; the signaller therefore must raise two torches on the left to show the recipient that he must look at the second tablet; then he will raise five on the right, because κ is the fifth letter in the group,[14] which the recipient must thereupon write on his tablet. Then the signaller must raise four torches on the left, for ρ is in that group, and two on the right, because it is the second in the fourth group, and the recipient will write ρ on his tablet: and so on for the other letters.
[47.] Now everything that happens can be definitely imparted by means of this invention; but the number of torches employed is large, because each letter has to be indicated by two series of them: still, if proper preparations are made, the thing can be adequately carried out. But whichever method is employed, those who use it must practise beforehand, in order that when the actual occasion for putting it in use arises they may be able to give each other the information without any hitch. For there are plenty of instances to show what a wide difference there is between the way an operation is carried out by men who hear of it for the first time, and by men who have become habituated to it. Many things which were considered not only difficult, but impossible at first, are, after an interval of time and practice, performed with the greatest ease. I could give many illustrations of the truth of this remark, but the clearest may be found in the art of reading. Put side by side a man who has never learnt his letters, though otherwise acute, and a child who has acquired the habit, and give the latter a book, and bid him read it: the former will clearly not be induced to believe that the reader has first to attend to the look of each of the letters, secondly to their sound-value, and thirdly to their combinations with others, each of which operation requires a certain time. Therefore when he sees the boy, without a pause for thought, reading off seven or five lines at a breath, he will not easily be induced to believe that he has not read the book before; and certainly not, if he is able also to observe the appropriate enunciation, the proper separations of the words, and the correct use of the rough and smooth breathings. The moral is, not to give up any useful accomplishment on account of its apparent difficulties, but to persevere till it becomes a matter of habit, which is the way mankind have obtained all good things. And especially is this right when the matters in question are such as are often of decisive importance to our safety.
I was led to say this much in connexion with my former assertion that “all the arts had made such progress in our age that most of them were reduced in a manner to exact sciences.” And therefore this too is a point in which history properly written is of the highest utility....
ANTIOCHUS IN PARTHIA, B.C. 209-5. See ch. [31].
[48.] The Apasiacae live between the rivers Oxus and Tanais, the former of which falls into the Hyrcanian Sea,The entrance of the Nomad Scythians into Hyrcania. the latter into the Palus Maeotis.[15] Both are large enough to be navigable; and it seems surprising how the Nomads managed to come by land into Hyrcania along with their horses. Two accounts are given of this affair, one of them probable, the other very surprising yet not impossible. The Oxus rises in the Caucasus, and being much augmented by tributaries in Bactria, it rushes through the level plain with a violent and turbid stream. When it reaches the desert it dashes its stream against some precipitous rocks with a force raised to such tremendous proportions by the mass of its waters, and the declivity down which it has descended, that it leaps from the rocks to the plain below leaving an interval of more than a stade between the rock and its falls. It is through this space that they say the Apasiacae went on foot with their horses into Hyrcania, under the fall, and keeping close to the rock. The other account is more probable on the face of it. It is said that, as the basin of the river has extensive flats into which it descends with violence, the force of the stream makes hollows in them, and opens chasms into which the water descends deep below the surface, and so is carried on for a short way, and then reappears: and that the barbarians, being well acquainted with the facts, make their way on horseback, over the space thus left dry, into Hyrcania....
[49.] News being brought that Euthydemus[16] with his force was at Tapuria, and that a body of ten thousandBattle on the river Arius between Antiochus and the Bactrians. horsemen were keeping guard at the passage of the river Arius, he decided to abandon the siege and attack these last. The river was three days’ march away. For two days therefore he marched at a moderate speed; but on the third, after dinner, he gave orders for the rest of his army to start next day at daybreak; while he himself, with the cavalry and light-armed troops and ten thousand peltasts, started in the night and pushed on at a great rate. For he was informed that the cavalry of the enemy kept guard by day on the bank of the river, but at night retired to a city more than twenty stades off. Having completed therefore the rest of the way under cover of night, the plains being excellent for riding, he got the greater part of his army across the river by daybreak, before the enemy came back. When their scouts told them what had happened, the horsemen of the Bactrians hastened to the rescue, and fell in with their opponents while on the march. Seeing that he must stand the first charge of the enemy, the king summoned the two thousand horsemen who were accustomed to fight round his own person; and issuing orders that the rest were to form their companies and squadrons, and take up their usual order on the ground on which they already were, he advanced with the two thousand cavalry, and met the charge of the advanced guard of the Bactrians. In this engagement Antiochus is reputed to have shown the greatest gallantry of any of his men. There was heavy loss on both sides: the king’s men conquered the first squadron, but when a second and a third charged, they began to be hard pressed and to suffer seriously. At that juncture, most of the cavalry being by this time on the ground, Panaetolus ordered a general advance; relieved the king and his squadrons; and, upon the Bactrians charging in loose order, forced them to turn and fly in confusion. They never drew rein before the charge of Panaetolus, until they rejoined Euthydemus, with a loss of more than half their number. The king’s cavalry on the contrary retired, after killing large numbers and taking a great many prisoners, and bivouacked by the side of the river. In this action the king had a horse killed under him, and lost some of his teeth by a blow on the mouth; and his whole bearing obtained him a reputation for bravery of the highest description. After this battle Euthydemus retreated in dismay with his army to the city of Zariaspa in Bactria....