. Scientific American Volume 03 Number 17 (October 1860). nables a spring of given power to operate with acurrent of half the force. Tlie inventor says this magnet has been thoroughlytested for telegraphing, and found practicable, and thatit can be easily applied to every kind of telegraph instru-ments. A patent for this invention was granted on the 15thof May, 1860, and further information in relation to the below, the first column shows the power of the coreswhen subjected to the battery alone with currents ofvarying force ; the second colnmn its constant powerunder the influence of the stee
. Scientific American Volume 03 Number 17 (October 1860). nables a spring of given power to operate with acurrent of half the force. Tlie inventor says this magnet has been thoroughlytested for telegraphing, and found practicable, and thatit can be easily applied to every kind of telegraph instru-ments. A patent for this invention was granted on the 15thof May, 1860, and further information in relation to the below, the first column shows the power of the coreswhen subjected to the battery alone with currents ofvarying force ; the second colnmn its constant powerunder the influence of the steel magnet alone; the thirdcolumn, the power when both were combined, and thefourth column the differences between the third and thesum of the first two. The close relation between thefirst and the fourth is very curious. The numbers areunits of the weight used: Power fromBattery steel Barer from twill G magi30 7 30 10 30 17 SO 30 90 34 30 89S3 58 Excess of combined power over both ?epsnte. 0709IS1818 ? Hi —JACOBS PORTFOLIO PAPER Several months since we bought one of the files hereillustrated, and we would not sell it (if we could notget another) for several times its cost. By its means,we are enabled to keep a file of the current volume of On the of the latter-named leaf, are twoeyes for the passage of the cords, a a. The newspaperbeing placed in the portfolio in the position shown, theneedles are pushed through it near the fold, and »r«then passed through the eyes in the edge of the leaf eyes on the free ends of the bands, b b; these,bands being forcibly drawn forward for the purpose. By this arrangement, the newspaper is not only heldin a perfectly protected and safe position, free frontcreases in its pages resulting from folds, but it is in afar more convenient form for handling than is obtainedby any other mode of filing known to us. The patent for this invention was procured (throughthe Scientific American Patent Agency) on the 15
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