CHAGNY 



CHAINS 



83 



winter are believed to be augmented by migration 

 from Scandinavia. The egg are usually four or 

 I'm- in number, of pale purplish buff colour, spar- 

 ingly streaked and spotted with reddish brown. 

 The chaffinch feeds in great part on insect-,, ami 

 d"e^ much service in summer by destroying aphides 

 iiiul caterpillars ; but eats also seeds, and is some- 

 times persecuted, because in spring it pulls up and 

 young turnips and radishes wnen in the seed- 

 leaf. It is particularly fond of the seeds of beeches 

 and conifers. Great numtare of chaffinches are 

 killed for the table in Italy. In Germany this 

 Kin! \vas formerly in the highest esteem as a song- 

 bird. Its notes are very clear and loud, but some 

 individuals greatly excel the ordinary multitude of 

 their species. The common Scotch name of the 

 challincli is Shilfa. 



Cliauin . an important railway junction and 



commercial centre in the French department of 



n!-et- Loire, on the Canal du Centre, 32 miles S. 



of Dijon. As the key of the roads to the Loire 



district, it has been strongly fortified. Pop. 4291. 



Chagos Islands. See DIEGO GARCIA. 



C'llJlfilM's. a town of the republic of Colombia, 

 on the N. coast of the Isthmus of Panama, situated 

 at the mouth of the Chagres River. A poor place 

 at best, with a harbour for vessels drawing from 

 10 to 12 feet of water, it was almost forsaken on 

 the stoppage of the Panama Canal. Pop. 1000. 

 The river Chagres rises about 10 miles NE. of 

 Panama, makes an immense bend round to the NE., 

 and enters the Caribbean Sea. Though towards its 

 mouth it varies in depth from 16 to 3u feet, it is, by 

 reason of its rapidity and its falls, of little use for 

 navigation. The line of the Panama Canal (see 

 PANAMA) lay partly by the valley of the Chagres. 



Chailln, PAUL DU. See Du CHAILLU. 



Chain, in Surveying (called Gunter's Chain, 

 from its inventor, Edmund Gunter, q.v. ), is a mea- 

 sure of 22 yards long, composed of 100 iron links, 

 each of which is thus 7 '92 inches long. As an 

 acre contains 4840 square yards, 10 square chains 

 (22x22x10 = 4840 square yards) or 100,000 

 square links make an acre. 



Chain Cable. See CABLE. 



Chain-mail, or CHAIN-ARMOUR, much used in 

 Europe in the 12th and 13th centuries, and still 



used in India 



./^^^V^V^^x^fev ami the f in f e ' 



rior of the 



Asiatic conti- 

 nent, consists 

 of hammered 

 iron links, con- 

 nected together 

 by riveted 

 links so that 

 each link em- 

 braces four 

 others, and worked into the form of a garment. 

 Such armour was much more flexible and con- 

 venient to the wearer than that which was formed 

 >f st>el or brass plates, but was less fitted to bear 

 the thrust of a lance. See ARMOUR. 



Chain-plates, on shipboard (wood vessels), 



are iron plates bolted below the channels to serve 



as attachments for the dead-eyes, through which 



landing rigging or shrouds and back -stays are 



and secured. In most of the modern iron-steel 



vessels rigging-screws take the place of the older 



dead-eyes, the chain-plates to which they are 



attached consisting simply of flat palms, having 



an eye projection, riveted to the inside of the sheer 



or top strake of shell plating. 



Chains. Chain-making being a distinct trade 

 f itself, thoroughly reliable chains can only be 



Piece of Chain-armour. 



made by men trained to the work, although 

 some of the very small nixes of common chain* 

 are made by women, boys, and girls. ChainH 

 are of two generally distinct kinds short-link 

 or u nsi mlded (frequently called close-link) chain, 

 and stud-link or stayed chain. The former u-uall v 

 embraces the smaller sizes of chain up to 1 A im-ln-, 

 and the latter comprises ships' cables and other 

 heavy chains. Short-link chain in made in the 

 following manner : The end of the bar from which 

 the link is to be made is heated, then cut to 

 gauge, and while still hot is bent into I "form ; the 

 free ends are then heated to a white heat and flat- 

 tened or scarphed by a hammer, and in this state 

 they are brought together and welded so as to form 

 the other end of the link. The flattening or scarph- 

 ing of the two ends and the closing of them being 

 all done in one heat, the scarphed ends are again 

 heated to welding-point, and the link is placed in a 

 suitable recess under a hollow-faced tool, worked 

 mechanically, which strikes the roughened weld 

 and ultimately finishes it off as smooth as the other 

 end of the link. The result is the finished link, 

 and when the first has been completed, another 

 piece of iron is bent in the same way and threaded 

 or rove through it, and another link formed and 

 finished in the same manner as the first. In this 

 way each successive link is added until the required 

 length of chain is made. 



The foregoing illustrates the way in which 

 chains generally are made, but as a rule, links 

 of chains of 1-inch diameter and over are welded 

 at the side instead of at the end, and a stud 

 or stay-pin is welded across from side to side of 

 the link. The larger sizes of chains and chain- 

 cables are made by men, and the expert workman 

 when employed making first-class chains of all 

 descriptions gets an extra price for his skill and 

 labour. Common (not to say inferior) chains, 

 however, are too often welcomed by bargain-loving 

 users if they can at all be made to pass the statu- 

 tory tests. Chains which stand certain of the 

 standard tests may be found totally unequal to 

 meet certain others, and superior and inferior parts 

 are often purposely mingled in one chain by dis- 

 honest makers to cheapen production and defeat 

 the system of testing. The iron used for very 

 superior chains is selected not only for its tensile 

 strength and welding properties, but for its ductility, 

 as high tensile strength is not infrequently possessed 

 by a hard brittle iron, liable to snap upon the appli- 

 cation of a sudden jerk, and therefore totally un- 

 suited for chains. The system of testing cables 

 followed by Lloyd's Register Society well exem- 

 plifies what should be adopted in the case of all 

 chains. Every 15- fathom length is subject to a 

 fair standard strain, sufficient to detect bad work- 

 manship, by pulling asunder or opening any defec- 

 tive welds, yet not so severe as to injure the nature 

 of the material by crystallising it a result invari- 

 ably produced by overstraining. This standard 

 test, however, not being the extreme limit of strain 

 which the chain ought to bear in actual use at sea, 

 a few links are required to be cut out at random 

 from any part of each 15-fathom length, and sub- 

 mitted to a so-called breaking strain of 50 per cent. 

 in excess of the standard te-t. If these trial pieces 

 are found to withstand this extra strain satisfac- 

 torily, they are then assumed to represent a fair 

 average of the strength of that particular length to 

 which they belong. This operation being gone 

 through with satisfactory results in each length of 

 cable, the whole is then passed, and certified 

 accordingly. Any unsatisfactory lengths are con- 

 demned, marked, and sent back to the manufac- 

 turer. 



In his treatise on Chain Cablet and Chains, Mr 

 T. W. Trail, surveyor-in-chief to the Board of 



