[42] _Vide_ ‘Minutes of Proceedings of the Institution of Civil Engineers,’ vol. lviii. p. 95. (The first steam roller was made in the year 1864.) [43] The first steam roller used in England was, I believe, in the year 1872; in Paris about 1864. [44] This should be collected and “weathered” so as to get rid of mud and any organic matter in it. [45] In Paris 3 to 3·75 ton miles of roller are applied to every cubic yard of metal; in America 5 ton miles are thought necessary. [46] _Vide_ ‘Roads, Streets, and Pavements,’ by Q. A. Gillmore, p. 89. [47] _Vide_ Aveling and Porter’s pamphlet on ‘Steam Road Rolling,’ p. 32. [48] _Vide_ Aveling and Porter’s pamphlet on ‘Steam Road Rolling,’ p. 33. [49] _Vide_ ‘The Use of Steam Rollers,’ by A. W. Parry, Reading. [50] Some road surveyors contend that for gravelled roads 6-ton rollers are heavy enough, for macadam roads 12-ton rollers. [51] Traffic in making a roadway is apt to grind off the sharp edges and spoil the metal before it is set. [52] ‘Report on the Economy of Road Maintenance and Horse Draught through Steam Rolling, with special reference to the Metropolis,’ by Frederick A. Paget, C.E., etc. etc., London 1870, to which I refer my readers for many scientific and useful facts upon this subject. CHAPTER VIII. PITCHED PAVEMENTS. It has been asserted that where a roadway has a traffic exceeding 1000 vehicles per diem, that to maintain it as a macadamised roadway is not economical.[53] However that may be, it is unquestionable that for very heavy traffic blocks of hammer-dressed stone, laid upon a concrete or hard gravel bed, have been in use for a great number of years, and indeed the Romans, who were great road makers, introduced the system (the Archaic, as it is sometimes called) into this country more than 2000 years ago; the size of the paving stones was, however, much larger than modern science finds necessary.