. American engineer and railroad journal . pto the full capacity of the scale it weighed1,600 lbs., neither more nor less. The firstinference was that some part of the scalewas not solidly fitted, and that under thisload it settled to place. An initial load of30,000 lbs. was applied by steel bars placedso as to act as load springs, but withoutproducing any change in the action of themachine. The machine was then takenapart, but a very careful examination failedto detect any defect. Supposing that thedefect miglit be too small to be readilydiscovered, an effort was made to exagger-ate it and so
. American engineer and railroad journal . pto the full capacity of the scale it weighed1,600 lbs., neither more nor less. The firstinference was that some part of the scalewas not solidly fitted, and that under thisload it settled to place. An initial load of30,000 lbs. was applied by steel bars placedso as to act as load springs, but withoutproducing any change in the action of themachine. The machine was then takenapart, but a very careful examination failedto detect any defect. Supposing that thedefect miglit be too small to be readilydiscovered, an effort was made to exagger-ate it and so locate it by packing the leversupports out of level and in wind. Themachine required rebalancing, of course, but nothing that wedid disturbed the action of the weight, nor the sensitive-ness of the scale, nor the regularity of weighing when thecritical point was once passed. The screws and gearing ac-tuating the platen were then thought to be at fault, althoughit was impossible to see how they could cause any disturbance, Fig. SO Fig. 3S. Fig. 30 Fig. 31 but in order to avoid any question, an hydraulic chamber 3 diameter was made and secured to the underside of theplaten, and suspending bolts were provided so the platen couldbe adjusted closely to place by the screws and all lost motiontaken up by the suspending bolts ; pressure was applied bypumping liquid into this hydraulic chamber. The resultsdiffered in no way from those previously obtained, but by Vol. LXVIII, No. 4-] AND RAILROAD JOURNAL. 183 this time I had determined what the cause of the trouble was—namely, that we had been trying to weigh two kinds ofpressure without thinking that they might have different re-sults. I therefore coupled this hydraulic cylinder to a testingmachine scale, applied a pressure of about 150,000 lbs. on theplatform of the support testing machine, and put weights onthe poise frames of the testing machine scale until its needlestood at zero. We then ran the ton weight on, and, as I ex
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectrailroadengineering
