of study in order to acquire knowledge which would in that cafe be common, and obvious to all. But fince they are different, not only each from the other, but alfo from themselves, it is plainly a matter of great importance to know the laws by which they are feverally diminished or increased: for unless he be acquainted with the differences, how fhall a commander be able to measure with exactness the time of a concerted march, either by night or by day? How can he be affured, without this knowledge, that he fhall not either arrive too early or too late? It happens alfo on fuch occafions, and indeed on fuch alone, that the first of these mistakes is more dangerous than the other; for he who arrives too late, is only forced to abandon his defign. on perceiving his error, while he is yet at a diftance, and may return back again with fafety: but he who comes before the appointed time, being difcovered by the enemy upon his approach, not only fails in his intended march, but is in danger alfo of fuffering an entire defeat. It is time, which indeed principally governs in all human actions, and moft particularly in the art of war. A commander, therefore, fhould be perfectly acquainted with the time of the fummer and winter folftices, the equinoxes, and the different degrees of the diminution or increase of the nights and days, as they fall between the equinoxial points. For this is the only method that can enable him to adjuft his motions to the courfe of time.' After being well acquainted with the definitions here specified, our Author recommends a farther progrefs into practical aftronomy. For it is not lefs neceffary for a commander to know diftinctly the feveral portions of the day and night, in order to determine the proper hour of rifing, and putting the troops in motion; for, without beginning well, it is impoffible to obtain a happy end.'

"Now the time of the day may be eafily known by the fhadow from the fun, by the course which the fun takes, and by the different degrees of his elevation above the earth. But it is not fo eafy to diftinguifh the time of night, unless to those who are verfed in the doctrine of the fphere, and are able to follow the course of the twelve figns, and to mark their difpofition in the heavens. With this knowledge it is a matter of no difficulty; for though the nights are unequal, yet in the course of every night fix of the twelve figns are raised above the horizon; it neceffarily follows, that at the fame times of the night, equal parts of the twelve figns muft always appear. When it is known, then, what part of the zodiac the fun occupies in the day, nothing more is required than, at the time of his fetting, to draw a line diametrically through the circle: when this is done, as much as the zodiac fhall afterwards rife above the horizon, so much of the night will be alfo known. When the nights are cloudy, recourfe must be had to the moon; for this

planet

planet is of fuch a magnitude, that in whatever part of the heavens it may happen to be, the light of it may always be difcerned. It is fometimes from the time of its rifing, and fometimes from thofe of its fetting, that the hours of the night are to be computed. But it will first be requifite to know, with exactnefs, the different times of its rifing upon each feveral day; nor is this knowledge difficult to be obtained, for, as the courfe of the moon is completed in a fingle month, the right apprehenfion of the progrefs in that period will serve equally in all the reft.'

How the Author felt himself, on finishing this elaborate piece of aftronomy, we cannot tell; but if his feelings were any thing like our own after reading it, we fcruple not to declare, that his head must have been in the fame condition which our uncle Toby's was, after attending to his brother Shandy's explanation of Locke's Idea of Duration. His meaning is, however, good, as will more plainly appear from the following very fignal inftances which he gives of mifcarriages that have happened from a general's want of this kind of knowledge.

•

Cleomenes, the king of Sparta, when he had refolved to make an attempt upon Megalopolis, agreed with fome of the garrifon, who were ftationed upon that part of the wall that was called Coloum, that he would come with his forces in the night, about the time of the third watch; for this was the hour in which thefe men were appointed to take the guard. But not having before confidered, that at the time of the rifing of the Pleiades, the nights were extremely fhort, he did not begin his march from Lacedaemon till about the fetting of the fun: it was therefore full day before he arrived at the destined place. He had the rafhnefs, however, to attempt to ftorm the city, but was repulfed with difgrace and lofs, and was even in danger of fuffering an entire defeat. Whereas, on the other hand, if he had been only exact in the computation of the time, his friends might have fecured his entrance into the city, and the defign might have been attended with fuccefs.

Thus again, King Philip, when he attempted to take Melite, was guilty of a double error: for not only the ladders which he carried were too fhort, but he failed alfo with respect to time; for, inftead of coming to the place in the middle of the night, as had been concerted, when the people would have been all faft afleep, he began his march from Lariffa at an early hour; and having entered the territories of the Melitoans, as it was neither fafe for him to halt, left the enemy fhould gain notice of his approach, nor poffible to return back again without being perceived, he was compelled by neceffity to advance, and arrived at the city before the inhabitants were gone to reft: but as he could not fcale the walls, because the ladders were not proportioned

At

proportioned to the height, fo neither was he able to enter through the gate, because the time of the attack prevented his friends that were in the city from favouring his entrance. Jaft, therefore, having provoked the rage of the inhabitants, and loft many of his men, he was forced to return back without accomplishing his purpofe; and instructed all mankind, for the time to come, to be fufpicious of his defigns, and to fet themfelves on their guard against him.' To this example our Author adds another of the fame kind, in the cafe of Nicias the Athenian general, who having found a fair occafion for drawing his army from the fiege of Syracufe, made choice of the proper time of night, and had retreated to a fafe diftance undifcovered by the enemy, when it happened that the moon was fuddenly eclipfed. Being ftruck by this event, and vainly imagining that it portended fome misfortune, he immediately fufpended his march. The confequence was, that when he defigned to continue his retreat on the following night, the Syracufians having now gained notice of his motions, fell upon him as he marched, and rendered themfelves mafters both of the army and leaders. And yet, if he only had enquired of men that were acquainted with thefe matters, he might not only have not loft his own proper time, but have rendered the accident itself subfervient to his purpose, on account of the ignorance of the enemy. For the ignorance of others is the fureft way of conducting fkilful men to the accomplishment of their defigns. It is manifeft then, that fo much of aftronomy fhould be acquired, as may be neceffary upon fuch occafions: and in order to obtain fuccefs in military operations, the ftudies of aftronomy, geometry, and mathematics, are abfolute neceffary to complete the general.'

We perfectly agree with the ingenious writer in opinion, that à competent knowledge in mathematical learning, efpecially in the practical parts of it, is effentially neceffary to every one whole fituation is above the lower orders of mankind, and much more so to those who are in that line of life, which may poffibly lead them to the management of the higher concerns of human affairs, fuch as fharing in the administration, commanding of fleets, armies, &c. or being employed in other im→ portant national bufinefs. But after all that can be faid, half the misfortunes that are here recited could not poffibly happen in our age, unlefs to the lack of aftronomical knowledge, the general add forgetfulness alfo, and leave his watch behind him at his bed's head. Accurfed be those clocks and watches! They will, in the end, be the ruin of all science so that a man fhall not be able to thruft a morfel, with propriety, into any one calling or concern in human life; and it will be well, if REV. Dec. 1780. E e in

in time to come, the fcience of aftronomy, any more than the fucceffion of our ideas, be of any service to us at all.

The ftratagems made ufe of in war, to draw the enemy into an ambufcade, are innumerable; a fertile genius (fays Mr. Simes) will vary them almoft to infinity. A very common one, and which feldom fails of fuccefs, he thus defcribes :

"Detach an officer, with a small party, to infult the enemy, with orders to retire when purfued, and by that means gradually decoy his purfuer into a defile, both fides of which are lined with infantry. But in attempts of this nature, your main body must be fo near your ambuscade, as to be ready to fupport them, in cafe the enemy fhould have perceived your defign, and fall upon their rear. The officer who advances muft march very flow, left his horfes should be out of wind before he begins his retreat. If he falls in with any waggons in fight of the enemy, he muft appear to plunder them; but left no fuch opportunity should happen, it may not be improper to cause a few waggons to proceed from a neighbouring village for that purpofe; and if this will not do, he may then appear to have advanced with an intention to discover the pofition of the enemy and if they should continue inflexible, he may attack their advance guard. Another method of decoying the enemy into an ambuscade (our Author fays) is, to fend forty or fifty men into a village, not far from their camps, whilft you take poft, with your whole detachment, on the out-fkirts, fo as not to be perceived by the inhabitants. The officer who is fent into the village muft difmount his troop, but not fuffer his men to quit their horfes. He will then affemble the bailiff and peasants, and order them to provide a certain quantity of forage, which they are to transport in three or four hours from that time. His next business is, to detach fome of them to the neighbouring villages, with the like orders, with pofitive commands not to give the enemy intelligence of his being there; or in case they fhould be obliged to own it, to report his party much ftronger than it is. Thefe meffengers being difpatched, he muft fuffer no one to leave the village. In the mean while, he will collect as much forage as poffible. His videts are to be fo pofted, as to give intelligence of the enemy's approach, and the main body are to continue in their ambufcade, in the out-fkirts of the place.

"When the enemy appears (which they will not fail to do) he must endeavour to carry off his forage, till he has drawn them to the place prepared for their reception; upon which he will face about, and ftop them, till the troops in ambuscade have time to attack them in flank.'

Our Author speaks highly of redoubts, and of their use to an army drawn up in order of battle; and very judicioufly

fupports

fupports his opinion on this head by the teftimony and practice of the greatest generals that Europe has produced.

In the wars between Charles XII. king of Sweden, and Peter the Great, Czar of Mufcovy, the former of thefe illuftrious heroes (Mr. Simes obferves) was always victorious before the fatal battle of Pultowa. The fuperiority he had conftantly before maintained over the Mufcovites is almoft incredible: it was no unufual thing for 10 or 12,000 Swedes to force intrenchments, defended by 50, 60, or even 80,000 Mufcovites, and to I cut them to pieces. They never enquired after their numbers, but only after the place where they might be found.

The Czar Peter, who was the greatest man of his age, bore the bad fuccefs of that war with a patience equal to the greatness of his genius, and ftill perfifted in fighting, on account of exercising his troops, and inuring them to hardships. In the course of his adverfities, the king of Sweden laid fiege to Pultowa: upon which the Czar called a council of war, where it was a long time debated, and various opinions were given, concerning the ftep moft proper to be taken in this exigency. Some were for furrounding the king of Sweden with the Mufcovite army, and throwing up a large intrenchment, in order to oblige him to furrender. Others were for burning all the country within 100 leagues in circumference, to reduce him by famine; which opinion was far from being the worft, and was alfo moft conformable to that of the Czar. Others, however, objected to it, by obferving, that it could never be too late to have recourse to fuch an expedient; but that they ought to hazard a battle, because the town and its garrifon were in danger of not being carried, by the invincible obftinacy of the king of Sweden, where he would find a large magazine, and a fufficient fupply of every thing to enable him to pafs the defart with which they proposed to furround him. This being at length the determined opinion of the council, the Czar thus addreffed himfelf to them :

"Since we have come to a refolution to fight the King of Sweden, nothing remains but to agree about the method, and to make choice of that which promifes the moft fuccefs. The Swedes are well exercifed, well difciplined, adroit under arms, and impetuous in their charge. Our troops are not inferior to them in point of refolution; but they certainly are in many other refpects: it therefore becomes neceffary to fall on fome fcheme that may render this fuperiority of theirs useless to them. 'They have frequently forced our intrenchments, and have always defeated us in the open field by dint of art, and by the facility with which they form their manoeuvres. In order, then, to counterbalance these advantages in the enemy, I propofe to draw near to him; to throw up feveral redoubts in the front of Ee 2

Our