. The street railway review . The determination of the speed offered some difBculties at first,it being too great for the successful use of a counter or tacho-meter. A commutator of one break was arranged on the fly-wheel shaft and this connected through the battery circuit withan ear-phone in .an adjoining room. This arrangement workedsatisfactorily, giving a clear, musical tone, and the number of electrical tape. Careful observations convinced the writer thatllu ic was no ai)preeiable slip. ■|1h- tachometer used was of the usual rotary pendulum typean<l cnliliralcd several times by c
. The street railway review . The determination of the speed offered some difBculties at first,it being too great for the successful use of a counter or tacho-meter. A commutator of one break was arranged on the fly-wheel shaft and this connected through the battery circuit withan ear-phone in .an adjoining room. This arrangement workedsatisfactorily, giving a clear, musical tone, and the number of electrical tape. Careful observations convinced the writer thatllu ic was no ai)preeiable slip. ■|1h- tachometer used was of the usual rotary pendulum typean<l cnliliralcd several times by comparison with a speedcounter. riFTEEX-IXCII i)ieces cast from the same ladle as these wheels worelirokeu in the testing machine, and the following average valuesobtained for the breaking strength: Tension, 19,000 lbs. per sq. in. Cross-breaking, 39,000 lbs. per sq. wiheels were all turned on the face and edges of the rim,and were carefully balanced by winding copper wire around thearms near the CAST-IKON FLY-WHEELS AFTER BUIir^ ribralions con-esponded closely to the speed as measured by areducing counter shaft and speed counter. It was soondiscovered that the audible tone produced by the machine itselfw-hen running at a high speed corresponded exactly to the tonein the ear-phone, and consequently the ear-phone was observers, having trained musical ears and provided withtuning forks, had no ditlicnlty in determining the pitch withinhalf a tone, the quarter tones being (>stimated. The error dueto this method did not exceed 5 per cent, and was probablyless than if an attempt had been made to get the speed with atachometer. The bm-sting speed of the wheels having rim jointswas too low to produce a musical tone with any distinctness, andit became necessary to resort to the tachometer. It was notdeemed safe for the observers to apply the instrument direcUyto the fly-wheel shaft, and a counter shaft reducing the speedfrom two to
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Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
