334 CARNEGIE INSTITUTION OF WASHINGTON. 



probably represent those from which came the famous Luna marble 

 introduced into Rome by Augustus. 



At the suggestion and with the assistance of Dr. Thomas Ashby, 

 Director of the British School in Rome, a careful examination was 

 undertaken of the Anio group of aqueducts, consisting of the Anio Vetus 

 of 272 B. c, the Aqua Marcia of 144 b. c, with the later Tepula and 

 Julia, and the Aqua Claudia and Anio Novus of the time of Claudius. 

 Despite the great length of the courses of these aqueducts and the 

 remote districts in which many of the scattered fragments are to be 

 found, the more extensive groups of remains, several hundred in number, 

 have been studied and partly classified. Of the remains not before 

 identified, the most important belong to the periods of Marcius, and of 

 Augustus, Titus, and Hadrian. The discovery of a new and distinct 

 type of concrete, or pseudo-concrete, in the underground channel of the 

 original Aqua Marcia, is of special significance for the history of that con- 

 struction, since it represents an earlier stage in its development than 

 has yet been found in any of the dated monuments in the city. 



The winter months were devoted almost exclusively to the collection 

 of data concerning the history of concrete construction in general, with 

 a view to the determination of the original sources of the knowledge 

 of this construction, of its first appearance in Italy, as well as of its 

 introduction and early development in Rome. As an aid in determin- 

 ing these questions, several weeks were spent, during March and April, 

 in the region of Cuma3 (the ancient center of many Greek and Oriental 

 influences) and at Pompeii. It seems clear from this investigation, as 

 Dr. Richard Delbriick holds in his work on Hellenistic monuments, 

 that southern Italy, during the earlier period, stood to Rome in the 

 relation of teacher rather than that of pupil. It is no less evident, 

 however, that a partial reversal in their relations took place during 

 the early empire, and that consequently the form of construction estab- 

 lished for Rome will serve as a safe basis for future work in that region. 

 At the suggestion of Dr. Ashby, a short time was spent in the vicinity 

 of Beneventum and Foggia, in the examination of the fine concrete 

 remains of a number of bridges and viaducts belonging to the ancient 

 Via Trajana, and to the parts of the Via Appia restored by Hadrian, 

 w^hich, owing to their remoteness from modern lines of travel, are still 

 remarkably well preserved. In their general technique, these struc- 

 tures show a distinct agreement with and dependence upon those of 

 the same period in Rome; but in certain details — notably in the use 

 of broken floor-tiles instead of roof-tiles for facing— they anticipate the 

 technique of the city of Rome by more than a half century. This 

 fact was further confirmed by a subsequent examination of the noted 

 amphitheater of Capua, which was found to belong wholly to the period 

 of Hadrian. 



The summer was spent in the final preparation of a general work 

 on the development of Roman concrete construction, which it is hoped 



