l . V I ~ L ~ ~ W l ~LI i. l. N l D EAGIA7I3EEIiVG CIIE'.IIISTl3Y
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to a rlist,aut point to control an operation in propess there is nou- a mere matter of detail. The ability of a carbon dioxide amlyzer to control through such a device as tlie angle transmitter the setting of dampers in such a way as to regulate itself exists already, and merely tiie need for it is necessary to make it actual practice. The Holland Vehicular Tunnel coniiecting Scm York City with NOWJerney is equipped
Vol. 20, No. 7
throughout, its length with continuous carbon monoxide recorders whose readings are transmitted to a distant point, where an operator signals the motorists to shut off their engines whenever the concentration reaches a danger point,. With the invention of new devices and the perfection of known methods, applicat,ion? of t,his kind are sure to become more numerous.
A New Achievement in Galvanizing' F. W. Young YILI.I*TION
I~.USINEIIRS, I N E O K P O X . A T ~ ~Newnnw. ~,
h'. J.
HE protectior, of cliernid equipment with zinc is To build a tank large enough to submerge tiit drum c.oiuoften thought to be of dubious value. Zinc is the pletely involved considerable expense and the problem of mrtal gcnerailp used for coatiiig metallic parts which weighting it against buoyancy presented difficulties. It will 1,c in contact with solutioiis used in the manufacture of vcas only necessary to galvanize t.he outer cylindrical surface, lit,lrojx~oe,siirce the salts produced in corrosion are a l < \ ~ ~ y shence a novel method of doing this work was adopted. Tlie whitc. a desirable fnetor in maintaining the color of Iiigh- drum was mounted in bearings and rotated with only about gr:& lit,hopone. It would not be considered good engi- one-fifth of its surface submerged in a shallow tank. The nceririg to design a ziix coating as a permanent covering speed of rotation was controlled through a variable-speed where tlic liquor is constrmtly corrosive or where the desired drive and the best speed determined by experiment. The prot.ect,ion depends upon the insoluble zinc salt that might rotation had to be slow enough to allow the plating to deposit bt: deposited upon tile surface, hut for the drying of crude arid fast enough i o prevent oxidation or drying of the surlitiioj~mezinc-coatrd equipmerit would be suitable. face exposed to the air.
