November 1, 1895.] 



KNOWLEDGE. 



24 L 



AN ILLUSTRATED 



MAGAZINE OF SCIENCE 



SIMPLY WORDED-EXACTLY DESCRIBED 



LONDON: NOVEMBER 1, 1895. 



CONTENTS. 



The Coinage of Rome. By tl. F. Hill. {Illustrated) ... 



Alabaster. By Richard Beixox 



Adhesive Organs in Animals. E.v R. Ltdekeee, 



B.A.Cantab.. F.R.S. {Illustrated) 



Spectrum Analysis.— II. By J. J. Siewaht, B.A.Cantab., 



B.Sc.Loud 



Science Notes. (Illustrated) ... 



Variable Red Stars. By Dr. A. Bijester, .Tun 



Photograph of the Nebulae Messier 78 and 



Herschel IV. 36 Orlonis. By Isaac Roberts, D Sc, 



F.R.S 



What is a Nebula .=> By E. Walter Mau.ndek, F.R.-A.S, 

 Letters ;— Edwi?? Holmes; E. JI. Antoniadi; Thos. W. 



Cowan ; I. G-. Ouseley (lllu-Jrated); Edivd. H. 



Thompson'; J. .J. Siewart. 



Notices of Books. (Illustrated) 



Earthworms. By C. F. JIarshall, M.D., B.Sc, F.R.G.S. 

 The Nitrogen of the Air as a Plant Food. By Geoeoe 



MctrOWAX, Pli.D 



Some Recent Patents. (Illustrated) 



Chess Column. By C. D. Locock, BXOxon 



PAGE 



241 

 245 



246 



249 

 250 

 251 



2.53 

 253 



254 

 25G 

 259 



260 

 262 

 263 



THE COINAGE OF ROME. 



By G. F. Hill. 



THE coinage of Rome, and of those parts of the 

 Italian x^eiuisula which did not come most 

 directly in contact with Greek civilization, offers 

 a striking contrast with the coinage of Greece. ' 

 Whereas, in the first place, the latter began with 

 the more precious metals, Italy at first contented herself 

 with bronze (nes) as her medium of exchange ; for the 

 coinage of silver and gold, though these metals were well 

 known, was not introduced until comparatively late. And 

 as Koman civilization generally was some centuries behind 

 that of Greece, it is not until the middle of the fifth cen- 

 tury that coinage, properly speaking, can at the most 

 liberal estimate be conceived to have begun in Rome ; while 

 there are reasons for putting the commencement nearly a 

 century later. Previonsly to the commencement of coinage 

 proper, the medium of exchange in Italy, as in other parts 

 of the world, had been cattle, values being reckoned in so 

 many oxen or sheep. The transition from this system to 

 the money system was made by the use of amorphous 

 lumps of bronze {aes rude) which circulated by weight. 

 Such pieces of metal cannot be called money, any more 



* See " Coinage of the G-reeks," in Knowledge, June, 1895. 



than their predecessors the sheep and oxen, and therefore 

 as numismatists we are only secondarily concerned 

 with them. It is, however, worth noting that long alter 

 acs rude had been superseded by coined money, it^ was 

 retained in use for certain special purposes. It was retained, 

 for instance, together with the scales in which it was 

 weighed, to perform a ceremony necessary to the validity 

 of the transfer of certain kinds of property. It was also 

 frequently devoted as an offering to various deities, in the 

 localities of whose shrines large quantities have been 

 found. 



It is with the «(■.^■ siinuitum (bronze marked with a design) 

 that our description of Roman coinage must begin. Homo 

 authorities, as we have already said, refer the beginning 

 of this coinage to the middle of the fifth century before 

 Christ, and this view is based on literary tradition ; but 

 even if the literary evidence can bear the interpretation 

 put upon it, it must always yield to the evidence of coins 

 themselves. And a comparison with the coinage of the 

 rest of the world proves conclusively that the earliest 

 pieces which have come down to us belong to the fourth 

 century, and by no means to its earliest years. 



We meet at the outset with an important difference from 

 Greek usage as regards the method cf coinage. Greek 

 coins were, almost without exception, struck with a die ; 

 but the bronze coinage of Italy was cast in a mould, and 

 the reason is obvious. The small value of copper as 

 compared with silver and gold necessitated the U3C of 

 large masses of metal to represent high denominations ; 

 and to strike such large masses with a die requires skill 

 and power which are ditlicalt to provide even in modern 

 times, not to mention the fact that few dies would stand 

 the strain. The metal was, therefore, given the required 

 form by casting, and even in later times the officials of 

 the Roaian mint retained the title of " commissioners for 

 cmtiiui and striking bronze, silver, and gold." In some 

 of the pieces projections at the sides of the coin mark the 

 points at wliich the liquid metal entered the mould 



(Fig. B). 



The earliest cast coinage took, for large denominations, 

 the shape of oblong bricks of metal, weighing from four to 

 five Roman pounds (Fig. A). Probably contemporary 

 with these are the smaller pieces of the more convenient 

 circular shape (Fig. B). This is what is known as 

 acs ;/;■«(■(• ("heavy bronze," so called, of course, in comparison 

 with the hghter coinage of later days). The large size of 

 the early pieces necessitated a thick as well as a broad 

 fabric. Bat with the gradual decrease in size of the pieces, 

 which we shall describe later, we arrive at a fabric hardly 

 differing from that of the Greeks. For about 209 b.c. the 

 smaller bronze coins were struck instead of cast, and some 

 twenty years liter the process of casting ceased entirely 

 to be employed. 



About the same time as the aes r/rave was introduced 

 the extension of the power of Rome over the peninsula 

 had compelled the Romans to adopt the customs of their 

 South Italian neighbours, and issue coins in silver and 

 even in gold. But it is characteristic of Roman con- 

 servatism I hat the first coins in these metals struck by 

 Roman authority were struclr, not for Rome itself, but for 

 the subject states, or rather as war money, to be used in the 

 wars waged by Rome against the Samnites, the Greek general 

 Pyrrhus" and the Carthaginians. About 3i2 b.c, when the 

 Romans began to interfere with the affairs of Campania, 

 the coinage hitherto issued by the cities in that district 

 was repla°ced by pieces of silver, bronze, and (a little 

 later) gold, issued by the Roman generals and bearing 

 the name of the Roman people (Figs. (5 and 7). Still, it 

 was not until some seventy years later that Rome struck 



