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34 THE LOCOMOTIVE, [March, pressure of the fulcrum against the lever. (It is plain that although the lever presses 7/jrwanl against the pin, the pin presses dowmcnrd against the lever.) Now since the lever does not tip either v;ay, but remains in equilibrium, it must be that the tipping effect of the weights is just balanced by the opposite tipping effect of the downward pressure of P against the lever. Now the tipping effect, or moment, of any force is proportional to the magnitude of the force, and also to the leverage it has. Thus to find the tendency of the weight A to turn the lever about the point Fas a center, we multiply 124 by 46;^ (46^ being the distance of this weight from V), which gives 5,735. This means that the weight A exerts precisely the same tipping effect that a weight of 5, 735 pounds would exert, if hung on the lever at a distance of one inch from V. <strong>The</strong> distances of B and C from V being 37| in. and 30:^ in., respectively, we find that their respective tipping effects are 37^ x 45 and 30^ x 45, or 1,076^ and 1,361^; so that A'^m « •// > C U Figs. 3 and 4.—Details op the Casting. the combined effect of the three weights is the same as the effect of a weight of 5,735 + 1,676| + l,361j = 8,773|^ lbs. hung on the lever at a distance of one inch from V. To this we may add the tipping effect of the lever's own weight, which we calculate in precisely the same manner, except that we first assume that it acts as though its weight were concentrated at its center. <strong>The</strong> center of the lever, being 25 inches from P, is 22| inches from F, so that its tipping effect is 22^ X 17 = 3785^. Adding this to 8,772|^ we obtain 9, 150|, which is the weight we must hang on the lever, one inch from F, to get the same tipping tendency that we get from the actual arrangement of things as shown in Fig. 1. Now since this tendency must be precisely equal to the tendency of the pin P to tip the lever in the opposite direction, in order to find the downward pressure of P we have merely to answer the question, what weight must be hung on the lever, 2| inches from F, to get the same tipping tendency that a weight of 9,150| lbs. gives when hung at a distance of one inch from F? And to answer this question we have merely to divide 9,150| by 2|, which gives 3, 328 lbs. (omitting fractions). Hence we conclude that in the arrangement shown in Fig. 1 there is a shearing strain of 3, 328 lbs. on the pin P, and therefore also a tensile strain of 3,328 lbs. on the casting which sujoport this pin. We have next to examine the fulcrum pin P, to see if it is strong enough to withstand this strain. This pin, which is shown best in Fig. 3, was threaded, being, in fact, a heavy machine screw with a round head. Its diameter at the base of the thread was .40 inch, so thatits effective sectional area was .40 x .40 x .7854 = .1357 sq. in. It will be observed that the pin must be double-sheared, if it fails ; and hence if we allow 70,300 lbs. per square inch of single section as the strength of iron exposed to double shear, the ultimate strength of the pin is found to be .1257 x 70,300 = 8,837 lbs. With
ltiy:{.) I" II !•; !.()( O.M () I I \ K. 35 a factdi- of salcly of 5 this , the clfcctive area to resist fracture would be ' U" — f) X I" — -2209 = •">1-">
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Page 40 and 41: 32 Incorporated 1866. THE LOCOMOTIV
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Page 46 and 47: 38 'i^il^ LOCOMOTl V i:. [Makcu, (1
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Page 56 and 57: 48 Incorporated 1866. THE LOC (J MO
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84 THE LOCOMOTIVE. [June, Boiler Ex
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86 THE LOCOMOTIVE. [June, (105.)
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88 THE LOCOMOTIVE. [June, The Heliu
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go THE LOCOMOTIVE. [JrxE, Mkt Elttt
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92 THE LOCOMOTIVE. [June, ills lett
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•94 THE LOCOMOTIVE [June, .21 ia
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96 Incorporated 1866. THE LOCOMOTIV
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98 THE LOCOMOTIVE. [July, worked ov
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: ^QO THE LOCOMOTIVE. [July, Inspec
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102 THE LOCOMOTIVE. [July, (132).
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104 THE LOCOMOTIVE. [July, " The am
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106 THE LOCOMOTIVE. [July, tttSttlt
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-iQQ THE LOCOMOTIVE. [July, and als
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110 THE LOCOMOTIVE. [July without t
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112 THE LOCOMOTIVE. [July. Incorpor
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114 THE LOCOMOTIVE. [August, to whi
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116 THE LOCOMOTIVE. [August, tion.
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118 THE LOCOMOTIVE. [August, (147.)
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-120 THE LOCOMOTIVE. [August, A lar
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•J22 THE LOCOMOTIVE. [August, git
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124 THE LOCOMOTIVE [August, hard en
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126 THE LOCOMOTIVE. [August, The Bu
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128 THE LOCOMOTIVE. [August. Incorp
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^30 THE LOCOMOTIVE. [September, pau
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132 THE LOCOMOTIVE. [September,. iu
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-[34 THE LOCOMOTIVE. [September, Fi
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136 THE LOCOMOTIVE, [September, .35
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138 THE LOCOMOTIVE, [September, add
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140 THE LOCOMOTIVE lSeptember, On a
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d42 THE LOCOMOTIVE. [September, cas
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144 Incorporated 1866. THE LOCOMOTI
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146 THE LOCOMOTIVE. [Octobek, in pl
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i48 THE LOCOMOTIVE. [October, Natur
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[50 THE LOCOMOTIVE. [October, Curti
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•152 THE LOCOMOTIVE. [Octobeb, an
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^54 THE LOCOMOTIVE. [Octobeb, Mkt e
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-[56 THE LOCOMOTIVE. [October, Tlie
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158 THE LOCOMOTIVE. [October, Of co
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162 THE LOCOMOTIVE. [November, that
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: 16^4 THE LOCOMOTIVE. [XOVEMLER, I
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166 THE LOCOMOTIVE. [November, boil
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168 THE LOCOMOTIVE. Sit Ktttmttit c
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170 THE LOCOMOTIVE. [November, KILL
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172 THE LOCOMOTIVE [November, Boile
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174 THE LOCOMOTIVE. [:November, sel
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178 THE LOCOMOTIVE. [December, grap
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: 180 THE LOCOMOTIVE. [December, In
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^82 THE LOCOMOTIVE. [December, that
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184 THE LOCOMOTIVE. [December, HART
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186 THE LOCOMOTIVE. [December, The
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188 THE LOCOMOTIVE [Decembeb, angle
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190 THE LOCOMOTIVE. [December, Such
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i92 Incorporated 1866. THE LOCOMOTI
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INDEX, Equivalent of heat, redeterm
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