(5.) The risk of frightening horses.
(6.) If too heavy a roller is used, the foundation of the roadway may be injured or the metal may be crushed instead of bedded.
(7.) The necessity of using so much binding material and water.
Before closing this chapter it will be necessary to say a few words upon rollers drawn by horses.
These are always unsatisfactory: they are expensive to use, as a large team of horses and a number of attendants are necessary; they are difficult to turn, and the horses’ feet displace almost as many stones as the roller compresses into their beds.
They cannot be of greater weight than 10 tons, even when on the hydrostatic principle, and they are clumsy and difficult of manipulation.
If a roller is to be used at all, let it be a steam road roller of the most modern description, and of the best manufacture.
[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.