268

MILLS.

not to be found : but Belisarius fell upon the ingenious con-trivance of placing boats upon the Tiber , on which heerected mills that were driven by the current. This ex-pedient was attended with complete success; and as manymills of this kind as were necessary were constructed.To destroy these, the besiegers threw into the stream logsof wood, dead bodies, &c. which floated down the riverinto the city ; but the besieged, by making use of booms,to stop them, were enabled to drag them out before theycould do any mischief. This seems to have been theorigin a{ floating mills; no record of them appearing before.By these means the use of water-mills became very muchextended; for floating mills can be constructed almostupon any stream, without forming an artificial fall; theymay be stationed at the most convenient places, andthey rise and fall of themselves with the water. Theyare, however, attended with these inconveniences; theyrequire to be strongly secured; they often block up thestream too much, and move slowly; and they often stopwhen the water is too high, or when frozen.

After this improvement, the use of water-mills was neverlaid aside or forgotten, but was soon made known all overEurope ; and passages might be quoted, ad infinitum, inevery' century, to prove their continued use. The Roman,Salic, and other laws constantly provided for the securityof these mills, which they call molina or farinaria; and de-fine a punishment for such who destroy the sluices, or stealthe mill-irons (ferramentum). It is said, however, thatthere were water-mills in France and Germany a hundredyears before these law's had existence.

Tide-Mills. —At Venice and other places, there wereerected mills which regulated themselves by the motion ofthe waters, and were worked by the ebbing and flowing ofthe tide, and which every six hours changed the motionof their wheels. Of this species of mills, a new invention,or perhaps, rather an improvement of it was made inLondon , called a tide-mill; which may be seen in “ The“ Advancement of Arts, Manufactures, and Commerce,” bvW. Bailey. Lond. 1772.

Zanetti is said to have shown, by some old charters, thatsuch mills existed about the year 1044 ; but with still morecertainty in 1078, 1079, and 1107.

It appears, however, that hand and cattle mills were inmost places retained, after the use of proper water-mills,particularly in convents. They were used, because the other-wise lazy monks found the exercise they afforded beneficial