354 ANNUAL KEPORT SMITHSONIAN INSTITUTION, 193 4 



The personnel {familia) of the relays consisted of a chief {fiianceps) , 

 a kind of postmaster, and of freedmen performing the services of 

 clerks, grooms {stratores — one for 3 horses), mounted couriers, pos- 

 tilions or chariot messengers {veredarii) ^ farriers, veterinarians, etc. 

 As a rule, 20 post horses {veredi) were kept at the relay stations, 40 

 at the mansions, and a still larger number at the stations. 



LEGAL LOAD RESTRICTIONS UPON VEHICLES 



Permissible loads for vehicles, such as travelers, baggage, silver, 

 munitions, etc., were strictly limited and regulated according to the 

 strength of the draught animals. In this connection a law of Con- 

 stantine provided that hirotae — carriages with two wheels — should 

 be drawn by 1, 2, or 3 horses or mules, and the load limited to 

 144 English pounds {If) ; rliedae^ should be drawn by 8 horses in 

 summer and 10 in winter and carry a load not exceeding 718 English 

 pounds; while c<zrr?', drawn by the same number of horses as the 

 rhedae, were not permitted to carry more than 431 English pounds. ^ 

 These extremely narrow limits applied, however, only to fast ve- 

 hicles. Even when loads were quadrupled for slow freight trans- 

 portation, the weight would be equivalent to a maximum wheel load 

 of 718 English pounds,^ assuming equal distribution of the load upon 

 the four wheels. This load is less than half of the 2,000-pound 

 wheel load, which Telford in 1819 (8) recommended as the limit for 

 freight wagons in England, and it is only a small fraction of the 

 4,500-pound motor-truck wheel load permitted upon modern high- 

 ways in the United States. Furthermore, the rlieda^ which provided 

 a service similar to the French stagecoach of the year 1875, carried 

 a load of only 718 English pounds, whereas the stagecoach and omni- 

 bus, drawn at a trot, carried loads of 1,100 to 1,800 English pounds. 

 The heavy and massive construction of the Roman vehicles, the inade- 

 quate system of harnessing, the lack of draught power by the horses 

 of small stature, and the excessive grades of the roads were responsible 

 for the relatively light loads as compared with modern times. 



FRONT AXLE OF FOUR-WHEELED VEHICLES TURNED UPON A 



KINGBOLT 



There has been considerable discussion as to whether the front axle 

 of four-wheeled Roman vehicles was a rigid unit, or whether it turned 

 upon a kingbolt as it does in modern vehicles. Some authors claim 

 that the straight course of Roman roads was necessitated by the in- 



' The as, or Roman pound, weighed 326.337 grams which is nearly three-fourths of 

 the present English pound avoirdupois weighing 453.59 grams. 



* Net loads, exclusive of the weight of the vehicle, are used in this comparison. The 

 4,500-pound net load for the motor truck is the equivalent of a 9,000-pound gross wheel 

 load. 



