Page:Encyclopædia Britannica, Ninth Edition, v. 20.djvu/612

588 

Cleansing.—The principal streets of a are generally cleansed, either by hand-sweeping and hand-scraping or by s. ’s consists of a series of revolving s on an endless, whereby the or  is swept up an incline into the cart. A less costly and cumbersome consists of a revolving  mounted obliquely, which sweeps a track 6  wide and leaves the dust or mud on one side to be gathered up by hand. A horse scraping- which delivers the mud at the side is also used, the blades of the scrapers being mounted obliquely and covering a width of 6. For general use, more especially in the country, scraping s worked by a man from side to side of the road, and scraping a width of about 4, are more convenient. All street surfaces suffer from the constant breaking up and disturbance to which they are subjected for the purpose of laying and repairing and. Subways, either under the middle of the road or near the kerbs, in which the may be laid and be always accessible, have often been advocated, and in a few instances have been constructed; but they have not hitherto found general favour.

Footways.— is the most suitable material for country or suburban footways; it should be bottomed with a coarser material, well, and should be laid with a roller. An inclination towards the kerb of about half an in a may be given, or the surface may be rounded, to throw off the wet. Where greater cleanliness is desirable and the traffic is not too great a  similar to that already described, but of smaller materials, makes a good and economical footway. The coating should be 2 or 3 es thick, composed of two or three layers each well rolled, the lower layer of materials of about 1 es gauge, and the upper of a half or a quarter of an gauge, with, or fine  chippings over all. footways require to be carefully made and must be allowed to set thoroughly before they are used. has a tendency to crack from contraction, especially when in a thin layer, and it is better to lay a footway in sections, with joints at intervals of about 2. slabs, especially when and constituting, make an excellent footway. The material is composed of crushed, , or other suitable material, mixed with and cast in moulds, and when set saturated with. This has proved more durable than  flagging, but it is more slippery, especially when made with. makes a good and pleasant foot, but is somewhat expensive considering its durability; it is apt to wear unevenly and to scale off when the is not of the best quality. It should not be laid of a less thickness than 2 es; 2 or 3 es are more usual. The flags should be square jointed, not under-cut at the edges, and should be well bedded and jointed with. is much more durable than and wears more evenly; it is impervious to wet and dries quickly by evaporation. The edges are sawn, and the hardness of the stone renders it difficult to cut it to irregular shapes or to fit openings. and made of  from  s are both very durable, though somewhat brittle. either laid as or compressed is extensively used for footways; the former is considered inferior in durability to  and the latter superior to it. should not be laid less than three-fourths of an thick on 4 es of , and 1  of  is desirable where there is great traffic.

Footways in a street must be retained by a kerbing of,,, or other sufficiently strong to stand the blows from to which it is subjected. It should be at least 4 es wide and 9 deep and in lengths of not less than 3. A kerb is usually about 12 by 6 es, either placed on edge or laid on the flat. When set on edge a kerb is generally bedded on with a ; when laid on the flat a  bed is desirable.

In a street pitched or channels are required, to prevent the wash of the surface  from undermining the kerb. The pitching consists of cubical blocks of hard about 4 es deep, bedded on  or, or preferably on a bed of. A channel consists of flat  about 1  wide inclining slightly towards the kerb. Moulded and  are also used both for side channelling and for kerbing. Such an inclination must be given to the channel as will bring the surface to gullies placed at proper intervals, and the level of the kerbing and consequently of the footway will depend to some extent on the surface  as well as on the levels of adjacent. To lay out a street satisfactorily the longitudinal and transverse sections must be considered in relation to these matters as well as to the levels of intersecting streets.

For fuller information on the subject see Sir Henry Parnell, A Treatise on Roads; Thomas Codrington, The Maintenance of Macadamized Roads; Debauve, Manuel de l’Inégnieur des Ponts et Chaussées; Annales des Ponts et Chaussées; Minutes of Proc. Inst. Civ. Eng., “Street Pavements,” vol. lviii. p.1, and “Wood Pavements,” vol. lxxviii. p.240; Reports by W. Haywood, to the commissioners of of the. (T. C.)

 ROANNE, a of, at the head of an in the, lies on the left  of the  in 46° 2′ 26″N. at a height of 912 above the. It is now the point of junction for the from  (262 s north-north-west) to  (50 s south-east), via, with the line from  to  (50 s south-south-east), and a branch connecting Roanne with ; and as the terminus of the Roanne-  (–) the  is the real starting-point of the. Besides the modern -house (–), it is enough to mention the ruins of a with a  dating from the, and a fine  of seven es connecting Roanne with the  suburb of  on the right  of the. is the staple, 1200 hands. ,, len , s, , and  are also produced; and, as the  stands in the centre of the  and  -field (output 4224  in 1884) and in the neighbourhood of the  -field, it has a considerable trade in  and. In Roanne had a  of 24,992.

Roanne (Rodomna, ; Roidomna, ) was an ancient of the and a station on the great from  to the. The absence of later than the time of  among the numerous local relics of the  seems to show that the  was sacked by the  in the. In the ship of Roanne became the property of the celebrated. A favourite scheme of his was to make the a great  centre by  of the, an affluent from the  which joins the  a little higher up; his death prevented its execution, but the subject has since been frequently revived.

 ROBBERY. See.

 ROBBIA,, the name of a family of great distinction in the annals of Florentine art. Its members are enumerated in chronological order below.

I. ( or  –) was the son of a Florentine named Simone di Marco della Robbia. According to Vasari, whose account of Luca’s early life is little to be trusted, he was apprenticed to the silversmith Leonardo di Ser Giovanni, who from to  was working on the grand silver altar frontal for the cathedral at  ; this, however, appears doubtful from the great age which it would give to Leonardo, and it is more probable that Luca was a pupil of Ghiberti. During the early part of his life Luca executed many important and exceedingly beautiful pieces of sculpture in marble and bronze. In technical skill he was quite the equal of Ghiberti, and, while possessing all Donatello’s vigour, dramatic power, and originality, he very frequently excelled him in grace of attitude and soft beauty of expression. No sculptured work of the great 15th century ever surpassed the singing gallery which Luca made for the cathedral at Florence between and, with its ten magnificent panels of singing angels and dancing boys, far exceeding in beauty those which Donatello in  sculptured for the opposite gallery in the same choir. This magnificent work now lies scattered in various parts of the