300 On Chain Cables or Moorings. 



dency of forces applied as before mentioned to curved or twisted 

 links is to convert tlie curves or distortions into straight portions, 

 as above described ; it follows, that liidis presenting in their 

 original construction, straight parts between the points of strain, 

 are the strongest that can be made with an equal portion of 

 metal ; and lience, links v\'ith parallel sides and senii-circular 

 ends would in every case be j)referred, were it not necessary to 

 the ijuality of good chain, that it should be able to resist lateral 

 violence as well as a general strain operating Ijy stretching. 

 Suppose that by anv accident the link figure 2 should have its 

 ends drawn towards Y and Z, while a resisting body at X op- 

 poses its motion in the direction of the applied forces, the side 

 of the link next to X would be bent inward ; and if in such a 

 link a stay like AGB were introduced, then the link would be 

 solicited bv the said force to assume a form somewhat like 

 figure 4. From the jireceding considerations it is evident that, 

 of all the forms and constructions that can be given to a link, 

 that form and construction which shall he able to convert a la- 

 teral into an end strain, by yielding jiroper support to the op- 

 posite sides of the link, is the one that should be preferred : and 

 of such a foim and construction is the link figure 5, with my 

 broad-ended stay introduced between the sides of the link; for, if 

 this link (wiiidi presents its priuci])al substance and all its points 

 of resistance in the same place) be drawn tov/ards a and b, 

 a[,^ninst an obstacle c, it is apparent, from a bare inspection, that 

 tlie parts de and df, which are su])ported by the parts ge and 

 gf, must be drawn asunder before the link can gi\e way: for the 

 matter in eg and fg cannot be made to penetrate itself, and 

 the two sides are compelled to retain their relative positions by 

 my interposed broad-ended stay //, a cross section of which 

 through its middle is shown in figure 6. I need hardly add, that 

 at the time that the stay h is introduced the link is wide enough 

 to receive it ; and the link being red hot at the time of its in- 

 troduction, and being pressed home to the stay by a die or press, 

 or any suitable mechanical means, takes a fast hold of it, and. 

 retains it in its place. Other ways of introducing and retaining 

 in its place my broad-ended stay may be employed ; but I have 

 found the preceding exceedingly simple and efficacious. On 

 mv broad-ended stavs I have only further to remark, that they 

 should embrace the whole or tlie greater portion of the opposite 

 curved parts of the middle of the link ; and even if the middle 

 of the link be made to form two opposite obtuse angles, the ends 

 of the stay should not embrace much less than the proportion 

 exhibited in figure 5. But in making the said ends to embrace 

 any larger portions, provided sufficient room is- left for the play 



of 



