the ballast necessary for the crane towers the weight of the engine should be considered. Access to the platform is obtained by ladders fixed either inside or outside one of the queen legs. With the exception of the boards forming the working platform, which are usually spiked down, the timbers of a tower gantry should all be connected by screw bolts and nuts.
Fig. 4.
Swinging scaffolds are useful for executing light repairs to a building. Perhaps the simplest form of swinging scaffold is the “boatswain’s boat,” so called from its being chiefly used for the painting or examination of the sides of ships, but it is dangerous to work from and a light wind will cause it to swing to and fro, and owing to the extremely awkward position occupied by the Workman there is difficulty in doing good work from it. A better, safer and more comfortable arrangement, the “painter’s boat” (fig. 4), is suspended by blocks and falls from two cantilever “jibs” fixed in the upper part of the building. The positions of the jibs are altered as required. The ends of the suspension ropes are fastened securely to the cradle, and by altering their length the workmen can adjust it to the proper height for working. These boats are usually constructed with a framework of iron and fitted with edge boards and guard rails all round. Like the “ boatswain's boat ” they sway considerably in the wind.
An improved form of cradle has been patented which is swung on block runners working along a. tight wire cable stretched between two jibs. Block tackle is used to raise or lower the cradle, and horizontal movement also is obtained by light guy lines working over pulleys at the jibs and secured to the tops of the suspension ropes. All adjustments can be made from the cradle with perfect safety. The guy lines steady the boat to some extent and prevent it from swinging in the wind.
Tall chimney shafts may be erected by internal scaffolding only, or by a combination of external and internal staging. The latter method is often adopted when the lower part of the shaft is designed with ornamental brickwork, string courses, panels, &c., and it is important that this work should be carefully finished. An external scaffold is therefore carried up until plain work not more than 2 or 212 bricks thick is reached, when the remainder can be completed by “overhand” work from an internal scaffold. The offsets made in the brickwork on the inside are used to support the limbering. For the repair of tall chimneys, light ladders are erected one above the other by a steeplejack and his assistants, each being lashed to the one below it and secured to the brickwork by dog-hooks driven in the joints. When the top of the chimney is reached balk timbers are raised by pulleys and laid across the top. From these are swung cradles from which the defective work is made good. If the work or weather demand a more stable scaffold, a light but strong framework of putlogs held together with iron bolts is fixed on each side of the shaft with iron hold fasts, and a platform of boards is laid upon them. For circular chimneys pieces of timber cut to a curve to fit the brickwork are clamped with iron to the putlogs to prevent them from bending when the bolts connecting the two frames are screwed up.
In England, the Factory and Workshop Act of 1901 empowers the secretary of state to make regulations respecting any dangerous “ machinery, plant, process, or description of manual labour.” No regulations affecting the building trade have been made, however, but a memorandum was issued in 1902 by the Home Office with the following Accidents. suggestions for the prevention of scaffold accidents:—
1. All working platforms above the height of 10 ft., taken from the adjacent ground level, should, before employment takes place thereon, be provided throughout their entire length, on the outside and at the ends,
(a) with a guard rail fixed at a height of 3 ft. 6 in. above the scaffold boards. Openings may be left for workmen to land from the ladders and for the landing of materials;
2. All “ runs " or similar means of communication between different portions of a scaffold or building should be not less than 18 in. wide. If composed of two or more boards they should be fastened together in such a manner as to prevent unequal sagging.
3. Scaffold boards forming part of a working platform should be supported at each end by a putlog, and should not proiect more than 6 in. beyond it unless lapped by another board, which should rest partly on or over the same putlog and partly upon putlogs other than those upon which the supported board rests. In such cases where the scaffold boards rest upon brackets, the foregoing suggestion should read as if the word bracket replaced the word putlog.
N.B. Experiments have shown that a board with not more than a 6 in. projection over a putlog can be considered safe from trapping or tilting.
4. All supports to centring should be carried from a solid foundation.
5. In places where the scaffolding has been sublet to a contractor, the employer should satisfy himself, before allowing work to proceed thereon, that the foregoing suggestions have been complied with, and (tlhat the material used in the construction of the scaffold is soun
See J. F. Hurst, Tredgold's Carpentry; A. G. H. Thatcher, Scaffolding. (J. Bt.)
SCALA NUOVA (Turk. Kush-Adasi), also known as New
Ephesus, a well-protected harbour on the west coast of Asia
Minor in the vilayet of Aidin, opposite Samos. The site of the
ancient Marathesium is close by on the S. It is connected with
the railway station of Ayassoluk by a diligence service. Before
the opening of the Smyrna-Aidin railway its road stead was
frequented by vessels trading with the Anatolian coast, and
it has often been proposed to connect it with the railway system
by a branch line, and thus enable it to compete with Smyrna.
In the absence of this the town is rapidly on the decline.
The population is not over 7000. The trade is of merely local
interest. (D. G. H.)
SCALD, an ancient Scandinavian bard who recited or sang at
feasts compositions in honour of chiefs and famous men and their
deeds. This word represents the Icel. skāld, Dan. skald, Swed.
skjald, the regular term for a poet. Authorities differ as to its
derivation. It seems certain that the word was originally
derogatory in sense; some connect it with skālda, a pole, on
which libels were cut. Others, e.g. Skeat, refer it to Swed. skalla,
Icel. skjalla, to make a loud noise or clatter, and take the original
sense to have been a “ loud talker.” This would link the word
with “ scold," to rail at, find fault with, which is formed from
Dutch schold, past tense of scheldan, cf. Ger. schelten, in the same
sense.
Of different origin is the verb “ scald," to burn or injure the skin or flesh by hot liquid or steam (see Burns and Scalds); also to cleanse an object, or to remove hair, bristles, feathers &c., from an animal, by exposure to moist heat, such as boiling water, steam, &c. This word is derived from the O. Fr. escalder, eschauder, mod. échauder, Lat. excaldare, to wash with hot water (caldus, calidus, hot).
SCALE (1) A small thin flake, plate or shell. The word. in O. Eng. is sceale, so bean-sceale, the husk or pod of a bean; cognate forms are found in Ger. Schale, O.H.G. Scale, from which the O. Fr. escale, modern écale, is borrowed. The ultimate root is seen in the closely allied “ shell,” and also in skull, scalp, shale and skill, and means to peel off, separate, divide. The word is used specifically (1) in botany, of the rudimentary flake like leaf forming the covering of the leaf-buds of deciduous trees and of the bracts of the cone in conifers; (2) in zoology, of the flat, hard structures of the epidermis or exoskeleton in fishes, reptiles. Thus in ichthyology the various types of scales are classed as cycloid (Gr. κίκλος, circle), where the growth is in layers, equally from the anterior and posterior edges; ctenoid (Gr. κτήν, comb), where the posterior edge is toothed; ganoid (Gr. γάνος, shining), with a hard enamelled surface and usually rhomboidal in shape, and placoid (Gr. πλάξ, tablet), as in the ossified papillae of the cutis of the shark. In reptiles the term is applied to the structures which form the covering, of the true reptiles, snakes and lizards. In entomology the downy covering
