[35, 36] No doubt the price of the machine varies with the price of iron, etc. [37] _Vide_ ‘Report of the Borough Surveyor of Birmingham to the Paving and Street Improvement Sub-Committee,’ p. 11. [38] _Vide_ ‘Proceedings of the Association of Municipal and Sanitary Engineers,’ vol. ii. p. 76. [39] _Vide_ ‘The Maintenance of Macadamised Roadways,’ by Thomas Codrington, p. 41. [40] _Vide_ ‘Proceedings of the Association of Municipal and Sanitary Engineers,’ vol. ii. p. 82. [41] _Vide_ ‘The Maintenance of Macadamised Roadways,’ by Thomas Codrington, p. 45. CHAPTER VII. ROAD ROLLING. The march of civilisation has decided that road rolling is a necessity for macadamised roads, instead of allowing the stones of which they are composed to be worn in by the traffic, as was formerly the custom. In Calcutta bullock rollers were used so long ago as the year 1855, and it was the cruelty of this operation that suggested to Mr. W. Clark the necessity for a steam roller,[42] the outcome of which was the well-known roller as manufactured and supplied by Messrs. Aveling and Porter of Rochester, and now so generally used throughout this country, as well as in American and other foreign towns.[43] Steam rolling saves money as well as suffering, and the legislature have recognised the importance of a sanitary authority becoming possessed of a steam roller by permitting money to be borrowed for the purchase of a roller as for a permanent work. (Sect. 234 Glenn’s Public Health Act 1875, footnote to Sub. Sect. (1).) Mr. Albert W. Parry, the Borough Surveyor of Reading, has prepared some tables on the subject of steam road rollers, from information he received on this subject, in answer to some questions he addressed to the surveyors of a number of towns a few years ago. It appears from this tabulated statement that thirty-three 15-ton steam rollers were in use, six 10-ton rollers, one 21-ton roller, one 8-ton roller, one 9¹⁄₂ ton roller, one 14¹⁄₂-ton roller, one 17-ton roller, and one 25-ton roller; this latter not being much used, as it was found to be too heavy. The average gross cost per annum of necessary repairs to the rollers, other than those which could be effected by the men in charge of it, amounted to 35_l._ 12_s._ The number of men employed to attend to the roller and cost of labour per day varied considerably, from one case (South Shields) where “one engine-man at 26_s._ per week, and an old scavenger with the flag” were found to be sufficient; to another (Gloucester) where the cost per day is stated as follows: “one man works the engine at 5_s._ per day, one boy with signal flag, 1_s._ 8_d._, two men spreading gravel or sand at 3_s._, two men watering and sweeping to keep water from running off in channels.”