Page:The American Cyclopædia (1879) Volume I.djvu/498

 466 ANCHOR or even gain in holding power, seem to have been regarded with suspicion. Hence the an- chor now in general use might almost have been described a century ago. In 1833 Lieut. Kodger of the English navy received letters patent for an improve- ment in the size and form of the palms, " having found by ex- perience that anchors with small palms will not only hold better than with large ones, but that the arms of the anchor, even with- out palms, have been found to take more se- cure hold of the ground than anchors of the old construction of similar weight and length." FIG. 2.-Admiralty Anchor. He flxe( j upon Qne fifth of the length of the arm as a suitable propor- tion for the length or the depth of the palm. The palm of the anchor, instead of being flat, presents two inclined planes, calculated for cutting the sand or mud instead of resisting perpendicularly. The Lenox, Mitcheson, and Aylen anchors are all improvements on the old admiralty pattern; while the Isaac anchor, an American invention, has a flat bar of iron passing from palm to palm, in addition to which two other bars unite the ends of the stock to the centre of the shank, intended to prevent the fouling of the cable. A novel and in many respects important improve- ment is that of the Porter anchor, having five ship owners appointed by the lords of tl admiralty to test their relative merits. Tl names are arranged alphabetically: ANCHOR. !- li 1 bC.g K 5 4 2

8 1 2 1 Facility of itoring. Quick holding. O. 3 3 1 8 2 1 2 8 2 4 4 4 1 1 8 2 4 1 te '! J_ 1 1 4 4 2 8 2 4 Facility of tnuuport in boats. I to f 1$ E Admiralty. Aylen Porter, or I Honiball Isaac 4 7 2 1 6 Trial refused. 6 8 1 1 3 4 a s i
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2 2 4 6 1 1 1 8 2 2 8 4 1 2 1 8 2 2 6 6 8 4 ' 1 5 Lenox Mitcheson. Eodger..... Trotman... . FIG. 8. Trotman Anchor. movable flukes or arms; this anchor, with certain valuable alterations, is represented above as the "Trotraan anchor." It will be readily seen that, by the closing of the upper arm against the shank, the chances of fouling are greatly decreased, as also the danger of the ship's grounding upon her anchor in shal- low water. The accompanying table, showing the relative order in whicV the several anchors above mentioned stand with regard to each of the properties essential to a good anchor, was embodied in a report made by a committee of The estimated numerical values of these sev- eral anchors are as follows: Trotman, 1-28; Rodger, 1-26; Mitcheson, 1-20; Lenox, 1-18; Porter, 1-09; Aylen, 1'09; Admiralty, 1, stand- ard; Isaac, 0*73. Notwithstanding the above favorable report, the Trotman anchor has not been received with general favor by ship mas- ters, though largely used by the merchant steamers. In general service, anchors rank according to their size and weight, as follows : bower, sheet or stream, and kedge; and a competent authority recommends them in the following order: the Lenox and Rodger for bower, Mitcheson for sheet, and Trotman for a shore anchor. The anchor adopted by the United States navy is solid with an iron stock, and as a rule its weight is proportionally less than the English standard, our officers prefer- ring a smaller anchor with greater length of chain. The following table gives the relative size of chains to anchors of given weight, and is compiled from the navy regulations on this subject : Weight of anchor. Site of chain. 8,000 Ibe 2,, inches. 6,000 " 4.000 " 2,000 " 1,000 " " The following is a reduced table of " Lloyd's Regulations for the Number and Weights of Anchors for Merchant Vessels " : Shlp'i Tonnage. Bower. Strewn. Kedge. Bower, Wood Stock. Bower, Iron Stock. Stream. Kedge. H Ton*. Cwt. Cwt. Cwt. Cwt. Cwt. 60 2 1 1 8 4 H 100 2 1 1 5 7 21 1] 250 8 1 1 18 15 6 1 COO 8 1 2 28 26 9 1 1,000 8 1 2 85 41 12 1 8i 1,600 8 1 2 48 50 14 B, 4 2.1 M Ml 4 1 2 47 54 14 9 4* In addition to these various forms of com- mon' anchors, there are numerous devices de- signed for special service. Among these are the grapnel and mushroom anchors shown in fig. 4. The former is adapted for securing light craft, and the latter a solid concave