Conservation. Glass gauges replacing steel. Colonel H.B. Hambleton, Chief of Army Ordnance's Gage Section explains the virtues of a glass plug gauge to Mr. Thornton Lewis and Brigadier General H.F. Safford (left to right). Glass gauges are lighter and cheaper than steel, permit greater visibility in inspection, are not as much affected by room temperatures and heat of operators' hands, are not corroded by perspiration, need no protection against rusting, do not acquire burrs that would change the effective sizes. They can save the annual use of 250 tons of critical tool steel in government arsenals alone