. Scientific American Volume 05 Number 01 (July 1861). wing are those which have been generally used, rangedaccording to their order of fusibility :— l. 2. 3. 4. 5. Zinc 80 85 88 90 94 Copper 8 6 5 4 2 Aluminum 12 9 7 6 4 No. 4 is the one usually preferred, particularly for sol-dering smaller objects. In order to make the solder, the copper is first melted,the necessary aluminum is added, and stirred by means ofan iron spatula, unpolished, as it comes from the black-smith, adding also a little tallow ; the zinc is then added,avoiding too much heat, as this last metal is easily oxy-dized and is
. Scientific American Volume 05 Number 01 (July 1861). wing are those which have been generally used, rangedaccording to their order of fusibility :— l. 2. 3. 4. 5. Zinc 80 85 88 90 94 Copper 8 6 5 4 2 Aluminum 12 9 7 6 4 No. 4 is the one usually preferred, particularly for sol-dering smaller objects. In order to make the solder, the copper is first melted,the necessary aluminum is added, and stirred by means ofan iron spatula, unpolished, as it comes from the black-smith, adding also a little tallow ; the zinc is then added,avoiding too much heat, as this last metal is easily oxy-dized and is very volatile. SIGOTJRNEYS PROJECTILE. A projectile for rifled cannon which possesses themerits of simplicity and strength, with no liability toget out of order when needed in the hour of battle,and which would at the same time give the accuracyand range due to that kind of arm, is considered bymilitary men-, a desideratum. Cast iron is not onlythe best but the cheapest^ material for the purpose ;but there has been an objection to its use, for the. casting c»uld not be made with sufficient accuracy tofit the bore and grooves with the necessary precision ;besides, the grooves were liable to serious objections seem to be overcome by Mr. Sig-ourneys improvement, represented in the accom-panying engravings. Figs. 1 and 2 are side views,and fig. 3 is a section of the bore and grooves, show-ing the relative depth and form of the latter. Theproper depth for these in a 24-pounder bore would betwo-tenths of an inch ; that for lesser calibers propor-tionately less. It will be seen that the projectile is ofthe usual cylindro-conoidal form, and is cast in onemass, the improvement consisting in so constructingthe cylindrical part that those portions only whichare finished come in contact with the bore andgrooves. The belts, b b, project slightly above themain body of the projectile, and are cast sufficientlylarge that they can be turned down to any re-quired fit or degree
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Keywords: ., bookcentury1800, bookdecade1860, booksubjectcombina, bookyear1861
