his study has been the work the title of which is above given. to this day appreciated by the natives, who for many centuries, have plundered the ruins to build or to patch up their The Italian antiquaries of the sevenown even more ruinous houses. The use teenth and eighteenth centuries, Nardini, of bricks among the Romans, who largely Ciampini, and their contemporaries, had employed them as building materials, not largely drawn on the store of historias we see in the familiar instance of the cal information afforded by the Latin Temple of Concord, has been more than brick inscriptions; Fabretti was, indeed, once the subject of the inquiry of indus- the first to set into any order the more trious antiquaries, for the Romans were remarkable of these, but his efforts were not content with producing the flat, tile- merely tentable; his collection of inscriplike brick which is so often to be met with tions was unclassified and incomplete. It in the lower portions of antique struc- was reserved to the worthy Abate tures scattered over the Empire, and that Gaetano Marini, the curator of the Vatiare known in England, but their bricks can Museum at the close of the last were indelibly stamped with the mark of century, to put together in a methodical their maker, the names of the reigning manner the stamped bricks of the choice consuls, and sometimes the year. From collection under his control; this task he this source, then, more than one patient admirably performed, preparing a learned archæologist has gathered a rich store of catalogue which however remained at information. But few inquirers have ventured far on the apparently arid and difficult road, which has hence remained little explored. Some curious information has, however, been lately thrown on the question by the researches of a French antiquary, M. Descemet, who has published in a recent number of the Bibliotheque des écoles d' Athénes et de Rome-an excellent publication, founded in 1877 and now at its seventeenth number-an article on the "Inscriptions doliaires latines or Roman brick-marks, more especially relative to the gens Domitia, in antique Rome the most renowned brick-makers. his death in an incomplete and manuscript form; but, such as it is, this manuscript preserved in the Vatican Library, has proved a mine of information to all subsequent writers. Marini's catalogue was arranged with admirable order and carefully classified, each brick of the collection being the subject of numerous commentaries. In spite of Marini's method, M. Descemet has adopted another system more suited to the requirements of the day, as rendered necessary by the considerable additions made to the list of brick inscriptions since the recent excavations. In his introduction, M. Descemet has From an epigraphical point of view carefully shown the importance of the brick marks of the Romans have the study of study of these brick these brick inscriparoused the attention of more than one tions, by which the date of the erecarchæologist, but the difficulties which tion of a building may be approximately have stood in the way of procuring the ascertained. But as the author hastens stamps, added to the enigmatical nature to add, the fact of bricks bearing dates, of the inscriptions themselves, have led or stamps being found in certain spots, the inquirers to fields where the results is not, of course, conclusive evidence to were more showy and more easily ob- the archæologist. Thns, in 1844, at Aix, tained. M. Descemet has long been in Provence, a brick of the year 123 was known to the antiquarian world; as far found, stamped with the mark of a Roman back as 1857 his "Fouilles de St. Sabina" workshop, but the presence of this brick attracted no little attention, as also, in can alone be accounted for by the effect 1876, his study, "Sur quelques Regles of accident, as it was scarcely possible de Briques antiques," published in the Bulletin de Correspondence Archaeologique. In possession of a valuable collection of stamps of his own, together with copies from the brick stamps of the Vatican Museum, M. Descemet had at his disposition more than ordinary sources of reference, and the result of that a town near Marseilles, so long famous for its pottery, should receive its bricks from Rome. On the shores of the Adriatic, at Pola and Zara, and in other towns of Istria and Dalmatia, the existence of a large number of bricks bearing the stamp of Rimini would tend to show that the brick trade, which still exists on both sides of the Adriatic, can be traced back at least eighteen centuries. the gens Domitia that attention has been paid. Why this gens has been chosen But apart from the geographical infor- the author explains. It would appear mation these stamped bricks afford, the that the gens Domitia possessed the inscriptions they bear throw not a little largest and most important of the brick light on an ill-known state of Roman mauufactories of ancient Rome. Apart society-the education of the slaves, who from this, the gens take no mean place in though we have classic evidence proving the history of Rome; in the person of that they were placed under school- the virtuous Marcus Aurelius, it ascended masters, would seem to have little pro- the imperial throne. From the brick fited by this education, as the inscriptions inscriptions gathered, the wealth of the it was their duty to stamp could only emperor would appear to have been have had their letters placed upside down enormous, as we learn by the large numor transposed (as they are often found) ber of workshops his gens employed, in by persons unable to read, who copied company with those of the gens Aria as well as they could a model under their which he inherited through his marriage eyes. with Faustina. How these stamps and brick inscrip- The interest of this quiet and appartions were made is a point of some ently little-inviting study would be thus uncertainty. Had the ancients moulds, seen to be great. Its historical value is or did they use movable types? This no less appreciable. We are comparalatter method would suppose a great tively far from the days when the history invention of the fifteenth century to have of ancient times was merely gathered been forestalled. M. Descemet, who de- from former texts; the aid afforded by votes some pages to the discussion of the numismatics and epigraphy is largely question, concludes in favor of the mould, called into requisition by the more serious such as we see examples of in more than modern historians. This little work of one national collection. The stamp was M. Descemet shows us how, even from cut in relief, or incised, and then-like the humble sources of the brick inscripthe butter-print of the present day- tions, important facts may be gathered. made use of. As for the character of The careful and beautifully cut Roman the spelling to be met with, this would stone inscriptions, so easy to read, are naturally arise from the want of. educa- not sufficient; the research can be carried tion of the workman. further, as we see for instance, in the stuAmong the various other points con- dy by M. Mumont on the ceramic inscripsidered by M. Descemet, the reason why tions of Greece, and even more strikingly the Roman bricks bear the date of their in the delightful study which M. Dressel production is not the least curious; but published some time since on the shatwhen Pliny's advice to the architect is tered debris of Monte Testaccio. M. remembered, only to make use of bricks Descemet's inquiry into the brick-marks when two years old-" ædificiis nonnisi of ancient Rome has already yielded some bimos probant,”—an explanation may, curious information; it is to be hoped perhaps, be found. A point has been that his success will encourage him to omitted by M. Descemet-one to which further study in this yet far from exattention is drawn in a recent able article hausted field of archæological research. in the Revue des Questions Historiques -in his neglecting to refer to the palms, pine cones, and animals so often found stamped on the Roman bricks. It is now known that with the potters whose name represented or recalled any object or animal, this object he stamped on the pottery or brick of his make. Thus, where we meet, with the stamped image of a wolf we may be sure that the workman's name was Lupus. As the title of the work shows, it is alone to the brick inscriptions relative to THE invention of binocular glasses has usually been attributed to Father de Rheita, who died at Ravenna in 1660. A printed placard has lately, however, been discovered in the Biblotheque by Signor Govi, which indicates that the credit of the invention is due to one D. Chorez, who lived at the sign of the "Compass" on the island of Notre-Dame, and who made the "lunettes" in 1625. AN INSTRUMENT FOR GAUGING THE FLOW.OF STREAMS. By M. DE PERRODIL. From the "Abstracts" of the Institution of Civil Engineers. THIS instrument, which is called a hydro-dynamometer, measures the velocity of a current by means of the torsion produced on a wire by the pressure of the water against a disc fastened to the end of the wire. ing the footbridge, any desired velocity could be imparted to the instrument, and the motion was so regulated as to keep the angle of torsion constant. The motion imparted to the water by the instrument passing through it was also observed, so that the actual velocity of the instrument through the water might be accurately ascertained. The velocity of the current is obtained by the equation v = c √a; where a is the angle of the torsion, and the value of c can be determined, either approximately from the coefficient of torsion of the material, or actually by experiment. A narrow frame, resembling in form The Author determined by experiment the longitudinal section of a tube termi- the value of c for the three differentnating in a bulb at the top, is immersed sized discs he employed. The instruvertically in the water, and turns, near ment was placed under one end of a small its upper extremity, on a vertical pivot footbridge revolving round a central at the end of the horizontal bar which axis, and it moved in an annular trough, encircles, at its other end, an upright 2 feet wide, containing water. By turnpole driven into the bed of the stream. A little, short, hollow cylinder, fastened to the under side of the bar exactly be low the pivot, receives the end of the vertical wire, which can be secured by a screw. The wire, which is situated in the axis of the frame, passes through the center of the horizontal graduated circle, fastened, above the water-level, across the widest part of the frame, and is secured to the bottom cross-stay of the frame. A needle, fastened to the wire just above the graduated circle, serves to measure the torsion of the wire. A disc, placed in the same plane as the frame, projects from the end of a horizontal arm fastened to the bottom of the frame. The instrument having been fixed with the disc at the desired depth, and on the up-stream side of the post, the disc assumesa position paralled to the current between the frame and the post, the needle and the frame are in the same plane, and the needle at the zero of the circle. On turning the needle by hand a torsion is produced on the wire, and the frame and disc may be thus made to assume a position perpendicular to the current. As the needle oscillates inconveniently, owing to variations in the velocity of the current, the wire is secured at the top by the screw as soon as the frame and disk are exactly perpendicular to the current, and the needle being fixed, the observer is free to note the oscillations of the graduated circle, and can read off the mean angle of torsion, which is independent of friction. A brass wire, 6 feet long and inch in diameter, was employed. A disc with a radius of 24 inches was used for velocities not exceeding 1 foot 4 inches per second, with a radius of 1 inch for velocities between 1 and 3 feet per second, and with a radius of inch for velocities between 3 and 10 feet per second. The distances in these three cases between the center of the wire and the centre of the disc were respectively 8 inches, 4 inches, and 2 inches. The Author considers Woltmann's hydrometric mill inferior to his instrument, as errors may occur in registering the number of turns of the mill, and also in marking the time, and as it has to be drawn out of the water to be read. Also the true equation for deducing the velocity from the results of observations with Woltmann's mill has not been thoroughly agreed upon, M. Chasles considering it to be an equation to a straight line, and Herr Baumgarten an equation to a parabola; but experiments conducted by the Author, and recorded in the last article, confirm the correctness of M. Chasles' view. A superiority is claimed for the instrument over Pitot's tube, on IRON AND STEEL NOTES ELDING CAST STEEL.-Two points must the following receipt for a welding compound: ENGINEERING STRUCTURES. fourth monthly official report on the St. HE ST. GOTHARD RAILWAY.-The eightyGothard Tunnel works affords some interesting information as to the condition of this under taking at the end of September last. From it we learn that as regards the main tunnel the been carried out, through the whole distance, enlargement to the full size of the arch had with the exception of a length of 131 ft. while length of 30,260 ft. The masonry of the lining the entire excavation had been completed for a of the arch was also completed for a length of 42,830 ft., and that the eastern and western sides for lengths of 32,440 ft. and 30,931 ft. respectively. Moreover, the portion of the tunnel completely finished, with waterways, refuges, etc., reached 30,504 ft., or about twothirds of the whole length. The heading for the curved entrance tunnel at the Airolo end WELDING CASTS Consideration chiefly in has also been made for a length of 233 ft., only month of September the number of men employed on the main tunnel averaged 3051, while the total value of the works executed up to the end of the month reached 49,835,545 francs, or nearly two millions sterling. The average temperature of the air in the central part of the tunnel averaged during the month 84.2 deg. Fahr., while the maximum temperature was 89 deg. The daily consumption of oil in the tunnel averaged 1274 lbs., and of dynamite 518 lbs. As regards the railways which are being made in connection with the main tunnel, there has been executed up to the end of Sep effecting the welding of steel: It is necessary 46 ft. remaining to be pierced. During the to render the film of oxidized iron on the surfaces to be united by welding as fluid as possisible, and some means must be found to restore to the steel the carbon eliminated during the process of heating to the welding temperature. According to the Revue Industrielle, M. Rust considers boric acid the most effectual in performing the former, and ferrocyanide of potassium in doing the latter. M. Rust considers the functions of the ferrocyanide to be also to restore to the steel nitrogen, upon which he looks as an important constituent of the metal. In 1850 a workman of Mulhouse, Alsace, sold Vol. XXIV.-No. 1.-6. tember on the line between Immensee and Fluelen 62 per cent. of the earthworks and 59 per cent. of the masonry structures; on the length between Fluelen and Goschenen, 75 and 67 per cent.; between Airolo and Biasca, 77 and 88 per cent. ; between Cadenazzo and Pirro, 67 and 73 per cent. ; and between Giubiasco and Lugano, 63 and 39 per cent. of the two classes of works respectively. Altogether in the five lengths of line named there had been finished an average of 72 per cent. of the earthworks and 67 per cent. of the masonry. Of the 49 tunnels on the lines of approach to the main tunnel the direction headings have been driven from end to end in the case of 34, there being included in this latter number all the tunnels on the Immensee-Fluelen section, while in the Airolo-Biasca section the headings are pierced in eight tunnels out of thirteen. The value of the works executed on the approach lines up to the end of September was, according to the prices paid to the contractors, 29,537,300 francs, or about £1,181,490. During the month of September the average number of workmen employed on these approach lines was 13,420, of which number 6,040 were engaged in the tunnels. IPHON OVER THE SAINT MARTIN CANAL-In 1 charges more than from about 40 to 50 cubic feet per second, for then the current has sufficient velocity to carry off along with it all the gases which it sets free.-Translated papers of the institution of Civil Engineers. ANITARY CONDITION OF THE ST. GOTHARD S TUNNEL.-Such alarming accounts have been made public of the sufferings of the men employed in this work, that, at the instance of the Italian Government, the Swiss Federal Council appointed a committee of medical men to inquire into the matter. They have reported that there is no epidemic disease as was supposed, but that the unhealthy conditions under which the laboris carried on, induce chest complaints and other internal diseases, lower the general health, and above all produce anæmia, or deficiency of red particles in the blood. The temperature rises as they penetrate into the tunnel from 12 deg. Cent. to 31 deg. Cent.; the air is loaded with aqueous vapor, carries a large proportion of carbonic acid, and is rendered additionally impure by miasma from stagnant water, smoke of lamps, and human exhalations; there is little light, the ventilation is deficient, and the men are often working in water. In winter matters become still worse, as the frost prevents the efectual working of the air pumps. From the commencement of the work up to March of this year, the deaths among the employes have been 122, of which 47 were by accidents; and in the first three months of 1880, 90 men were dismissed with anæmia. The habit so general among Continental workmen of working all seven days of the week must be counted as one of the sanitary disadvantages; for those who took days of rest were found to resist best the unhealthy influences. The company provides medical and hospital accommodation, and seems to do what is in its power for the health of its men, and the help of the families of those who succumb. NEW RAILWAY BRIDGE ACROSS THE Surder o carry out the new drainage works of the Bercy district, it was necessary to connect the sewers, which used to discharge into the Seine, with the main sewer on the opposite side of the St. Martin canal. This was accomplished by constructing an arched siphon over the canal, which, besides possess ing the interest of novelty, was not liable, like a reversed siphon going under the canal, to collect deposit in its central portion. The rise of the siphon is 26 feet 3 inches, which renders the entire exhaustion of the air more difficult to maintain, as the pressure inside the siphon, being only about one-fifth of an atmosphere, some of the gas contained in the water is set free. Tromps were adopted for removing the air and Two tromps with an inlet orifice of 1A TEES. For some time past the directgas. inch diameter, and an outlet of 4 inches, sufficed to make a vacuum in six minutes ors of the North Eastern Railway have felt which one tromp was then able to maintain. In that the existing railway bridge which crosses order to reduce, as far as possible, the consumption of water in working the tromps, the flow through the supply pipe is controlled by a float. The float closes a valve whenever the vacuum is complete, and opens it again as soon as a further exhaustion is needed. By thus regulating the supply, or by using a third tromp with an inlet orifice of only inch, and an outlet of 4 inches, the consumption of water was only from 10,600 to 12,300 cubic feet in twenty-four hours. The siphon has been surmounted by a chimney, raised to a height of 34 feet above the level of the sewers, at the top of which the tromps work. As the waters of the sewer cannot possibly be drawn up to this height, the tromps are by this means removed from all danger of obstruction. One important advantage of the method adopted is, that whereas lifting pumps might be unable to discharge the waters delivered after a great rainfall, the tromps are relieved from the necessity of working as soon as the siphon dis the river Tees at Stockton is not sufficient for the increasing traffic of the district. They have, therefore, recently decided to construct a new bridge, and the Tees Side Iron and Engine Works Co. [limited], Middlesbroughformerly Messrs. Hopkins, Gilkes & Co., who built the Tay Bridge-have been entrusted with the work. The erection of this bridge will form only a part of several proposed alterations, which will also include the diversion of the existing lines of rails, and the erection of a new iron station, which will be approached from Maudale road and Stockton Bridge road. The site of the new bridge will be a little to the east of the present one, and the structure will be so erected that it will carry the diversion of the Thornton road over the railway at a point where it intersects Darlington and Cleveland streets, thus giving improved facilities to the road traffic in these two important thoroughfares. The plans for the station have not yet been matured, but they will |