The naval architect's and shipbuilder's pocket-book of formulae, rules, and tables and marine engineer's and surveyor's handy book of reference (1884)
Mackrow, Clement · London, C. Lockwood and co. · leaf 154
o forces act in ^ig. 122. Fig. 123. the same direction, and fig. 123a case in which the componentsact in opposite directions. Let AB and CD represent thetwo forces; join ad and cb,cutting each other in e ; in DA(produced in fig. 123) take DP= BA; through F draw a lineparallel to the components;this… … AF = GH DF = GH 7. To find the resnltant of any number of parallel forces.Rule.—Take the sum of all those forces which act in one direction, and distinguish them as positive ; then take the sumof all the other forces which act in the contrary direction, anddistinguish them as negative. The…
