The Bridgeport times and evening farmer., 1918-09-06
IRIDIUM SHORTA ACE IS BY
 DR. R. B. MOORE
Most Decided Usefulness At the Present Time Is for
 Airplane Instruments.

Cripple Creek, Sept. IA shortage of radium was forecast by Dr. Richard B. Moore Of the United States Bureau or Mines in an address delivered hero today before the annual meeting of the American Institute of Mining En- gineers. Radium Is largely being used on the faces of watches and clocks and other similar purposes, the speak CT said. ''It is a great pity that our supply of rndium is being disseminated in this manner" said Dr. Moore. But as the physicians and surgeons of the country are not purchasing enough radium to make the industry finan- cial success, 1t is natural that the man. ufacturers should take other means of creating demand. The day is not far distant, in my judgment when we shall greatly regret the radium that has been lost in this way.
 "Radium has 8 mast decided useful ness at the present time; nine instru- ruents used on airplanes have dials made luminous with radium paint; 1t is employed in the same manned for compasses and gunsights. The eff cIency of night firing, with both ma chine guns cad artillery. has been greatly increased by the use of these luminous sights. Other uses cannot be specified, at the present time, ir a public paper.
 Tt is difficult to estimate the exac amount of radium in existence at the present time; probably it Is some where around OF. of radium element Considerably more than half thu amount of radium now in existence has come from Colorado and Utai carnotte ores.
 "Six years ago, the engineers of tn Bureau of Mines estimated that at tn current rate of production, the depos it's might last, commercially, 10 or years. At the present time, 1t is yer difficult to obtain ore. Most of tn deposits are owned by five operatin radium companies. The productiol has increased very greatly during tn war; and I am very doubtful whethe we can depend upon our carnotite de posits to yield commercial quantitie of ore for more than 6 or years long CT. It is my judgment that the field will not produce more than 100 ada tional grams of radium element at tn nost-of that much. This woul about double the worlds present sur ply, but, on account of the large u of radium in cancer treatment, sue an amount, although large scientific ally, would be small in proportion the probable demand.
 oF tho 6tSCp11 ination and loss of radium is to pro vide a substitute. Mesothorium Is a excellent substitute in many ways Ii haif-life period is much shorter tha that of radium. When first prepare 1t gradually increases in activit. comes to a maximum, and then begi1 to lose Its activity. After 'ripenine for about a year after prepared, 1t ca be used for luminous paint just as e ficiently as radium. Its usefulness ft such purpose will last for or year which Is as long as is required ft cheap watches, push-buttons, etc.
 "Mesothorium can be obtained as byproduct in the treatment of mon zite sand for the manufacture of tho ium notrate used in incadescent ma, ties. During the last year. the U. Bureau of Mines, has been experimen ing along these lines and has develo ed a process which is being put in the largest thorium plant in the cou try at the present time, and 1t
 hoped that before long mesothoriu can be substituted for some of the dium that is now being used in lun nous products.
 "Mesothorium can also be used cancer treatment although it's shc life makes it much less desirable this purpose than radium."