or, if we observe the distinction drawn by the author, Strategematicon Libri III. and Strategicon Liber unus, forming a sort of treatise on the art of war, developed in a collection of the sayings and doings of the most renowned leaders of antiquity. The anecdotes in the first book relate to the various contingencies which may precede a battle, those in the second to the battle itself and its results, those in the third to the forming and raising of sieges, while those in the fourth, or the comprehend various topics connected with the internal discipline of an army and the duties of the commander. This compilation, which presents no particular attractions in style, and seems to have been formed without any very critical investigation of the authorities from which some of the stories are derived, must have been published about A. D. 84, soon after the return of Frontinus from Britain, for we find Domitian named more than once with the title of Germanicus, together with frequent allusions to the German war, but no notice whatsoever of the Dacian or other subsequent campaigns.

, a treatise, composed, as we have already pointed out, after the year 97. The language is plain and unpretending, while the matter forms a valuable contribution to the history of architecture.

We learn from the preface to the that Frontinus had previously written an essay De Scientia Militari, and Aelian speaks of a disquisition on the tactics employed in the age of Homer, both of which are lost.

In the edition of this collection by Goesius (Amst. 1674) there is a fragment (p. 28-37) attributed to Frontinus, which gives an account of measures of length and geometric forms. In Goesius it is erroneously headed, De Agrorum Qualitate--a title which properly belongs to the following fragment. The writer states that, after having been diverted from his studies, by entering on a military life, his attention was again turned to the measurement of distances (as the height of mountains and the breadth of rivers), from the connection of the subject with his profession. Mention is made in this fragment of the Dacian victory, by which is probably meant the conquest of Dacia under Trajan, in A. D. 104. This fragment is wrongly attributed to Frontinus. Although some of the circumstances of the author's history seem to fit Hyginus (compare Hygin. p. 209, ed. Goes.), it is more likely that the author was Balbus, who wrote a treatise, , which is inserted in the collections of Antejustinian Law. In the principal manuscript (codex Arcerianus) of the the fragment is entitled .

In p. 38-39, Goes. is an interesting fragment of Frontinus in which are explained the distinctions between ager assignatus, ager mensura comprehensus, and ager areifinius. These are the three principal distinctions as to quality, but there is also an explanation of other terms, as ager subsecivus, ager extraclusus (Niebuhr, Hist. of Rome, vol. ii. app. i.). Professor C. Giraud, in his Paris, 1843, p. 7, n. 2, doubts whether the fragment is properly attributed to Frontinus, and seems inclined to refer it to Balbus. In support of this doubt he cites the of Polenus, p. 16. prefixed to the edition by Polenus of Frontinus, 4to. Patav. 1722. It should be observed that the fragment to which these doubts apply is not (as Giraud seems to suppose) the fragment (p. 38, Goes., p. 12, Giraud), but the fragment which we have already treated of in the preceding paragraph, addressed to Celsus, and wrongly headed in Goesius, p. 28.

Next follows (p. 39) the fragment headed , which consists of short and mutilated extracts from the beginnings of chapters in the work of Frontinus on the same subject. The which were fifteen in number, were disputes connected with land, most of which were decided not jure ordinario, but by agrimensores, who gave judgment according to the rules of their art. In other cases, or, perhaps, in earlier times three arbitri, appointed under a law of the Twelve Tables, or a single arbiter, appointed under the Lex Mamilia (Cic. de Leg. 1.21), pronounced a decision, after having received a report from agrimensores. Some account of these controversiae may be found in Walter, Gesch. des Röm. Rechts. p. 784-8, ed. 1840. In natural arrangement, the treatise follows the treatise because upon the quality of the land depend the rules for deciding disputes. The fragments are followed by commentaries (p. 44-89, Goes.) bearing the names of Aggenus Urbicus and Simplicius. The former seems to have been a Christian, who lived about the middle of the fifth century, and the so-called Liber Simplici owes its name to the absurd mistake of some hasty reader, who met with the following remark at the end of the first part of the commentary of Aggenus:--"Satis, ut puto, dilucide genera controversiarum exposui: nam et simplicius enarrare conditiones earum existimavi, quo facilius ad intellectum pertinerent."--(p. 62, 63, Goes.) The Liber Simplici, then, as some of the manuscripts import, is probably a work of Aggenus, and, from some expressions which it contains, seems to have been delivered orally as a lecture. A portion of it, never before published, was given to the world by Blume, in Rhein. Museum für Jurisp. vol. v. p. 369-7. These commentaries upon Frontinus are exceedingly confused and ill-written, the author having been a mere compiler, without any practical knowledge of the subject he was writing upon. Their chief value consists in the original passages of Frontinus and Hyginus which they preserve, for Hyginus, like Frontinus, wrote a treatise (which was first published by Blume, in Rhein. Museum. für Jurisp. vol. 7.138-172), and Aggenus, in making up his commentary on Frontinus, plagiarises the text of Hyginus. It is exceedingly difficult to determine precisely all the passages which belong textually to Frontinus in the commentary of Aggenus. The chief clue is the superiority of sense and diction in the original writer; and there can be no doubt that the epithet praestantissimus applied to such a monster as Domitian (p. 68, Goes.), must have proceeded from a contemporary of the emperor. The contains remarks on the status and transcendentin of which prohahly belong to Frontinas; but it also contains a long passage (p. 87-89, Goes.), which does not relate to the subject of Controversiae, and may have been introduced by an accidental transposition of leaves from a treatise De Conditionibus Agrorum of Siculus Flaccus. Walter (Gesch. des Röm. Rechts, p. 784, n. 64) attempts to restore to order the confused commentary of Aggenus. The in Goesius, p. 90 bears the following title, "Aggeni Urbici in Julium Frontinum Commentariorum liber secundus, qui Diazographus dicitur." It consists of a set of plates or drawings, which seem intended to illustrate the writings of Frontinus and

Next follows (p. 102-147, Goes.) a treatise, , which has been generally published under the name of Frontinus, but it is doubtful whether any part of it really belongs to our author. It is compiled from various sources, as the the the and contains much curious information, topographical and historical. That, in its present state, it cannot have been compiled by Frontinus is evident from the mention which it makes of later emperors, as Antoninus and Commodus. Some notes on this work by Andreas Scottus were printed by P. Burmann in his edition of Velleius Paterculus, p. 632-640. (Lug. Bat. 1719.) The chaotic fragment, called in Goesius, p. 128, Julii Frontini Siculi Praefatio, is quite out of place, and resembles the end of the first part of the Commentary of Aggenus Urbicus (p. 64, Goes.). The name Siculus joined to Frontinus appears to have been given from an ignorant confusion of Frontinus with Siculus Flaccus. In consequence of works having been wrongly attributed to Frontinus, which clearly could not have been written by the author of the treatises on Stratagems and on Aqueducts, some scholars, following Polenus, have supposed the existence of two writers of the same name, and have maintained that the writer on Stratagems and the Frontinus, of whom we possess some genuine remains in the collection of Agrimensores, were different persons. (Fabric. Biblioth. Lat. vol. iii. p. 311, ed. Ernesti.)

In Goesius, p. 215-219, is a fragment given without the name of any author, under the title In one manuscript it is ascribed to Hyginus, and in another to Julius Frontinus Siculus. Niebuhr attributes it to Frontinus. (Hist. of Rome, vol. ii. p. 623. n. 9, and p. 626. n. 22.)