File:Treatise on marine and naval architecture, or, Theory and practice blended in ship building. Illustrated with more than 50 engravings (1852) (14582957350).jpg

Identifier: treatiseonmarine00grif (find matches)
Title: Treatise on marine and naval architecture, or, Theory and practice blended in ship building. Illustrated with more than 50 engravings
Year: 1852 (1850s)
Authors: Griffiths, John W. (John Willis), 1809-1882
Subjects: Naval architecture
Publisher: New York : D. Appleton
Contributing Library: University of California Libraries
Digitizing Sponsor: Internet Archive

View Book Page: Book Viewer
About This Book: Catalog Entry
View All Images: All Images From Book
Click here to view book online to see this illustration in context in a browseable online version of this book.

Text Appearing Before Image:
nsions are given; in aword, we have at present nothing tosay to the builder who furnishes thedimensions of the spars, but to thespar-maker who makes them ; (they,however, are often confined to glaringerrors and manifest discrepancies bythe masters of vessels, who supposethey know about all.) We will com-pare the proportions given at the sev-eral settings-off of a yard with thosewe shall propose, and draw such in-ferences as the subject may demand.Assuming a lower yard to be 80 feetlong, and 20 inches in the slings, strikea centre line on the spar, (after spot-ting it to prevent its rolling,) middle it,and divide each half length into 4equal parts, which, with the middle andend, will make 5 spots or settings-off.The ordinary settings-off or sizes to beapplied at the several spots each sideof the centreline would be as follows:in the centre 10 inches ; at the first set-ting-off from the centre on each end.91; at the second setting-off or spot,St inches ; at the third, 7 inches ; and Sii
Text Appearing After Image:
IMAGE: Universe (ship, 1850) See also fig. 19. MARINE AND NAVAL ARCHITECTURE. ,VA at the fourth spot or end, 41 inches.Thus we discover that in the slingsthe yard is 20 inches; at the first set-ting-off 191 inches; at the second,17£ inches ; at the third, 14 inches ;and at the end, 9i inches. We haveshown another kind of sweep in Fig-.3, that will furnish better proportionsthan that of Fig. 2: by applying thesettings-off as taken from the diagramsto the scale of three-quarters of aninch, we shall discover the variationsin the size of the same yard, of thesame size in the slings, and an equalnumber of settings-off. The first set-ting-off from the sling furnishes thesame as the first, 19£ inches; the sec-ond, 16? inches ; the third, 12 inches ;and the end, 6f inches. Now, we hesi-tate not to say. that spar-makers them-selves will acknowledge that a yardmade by those dimensions would be aslikely to break any where else as inthe slings, and not any more ; of coursethere should be an allowance in sizefor the weakening tendency of the

Note About Images