The age-herald., 1902-01-06
Cooper HewiH.s New Light

I as large as three inches, and from less than three inches in length up to over ten l feet. giving from less than ten candles up to fully 5000. Lamps of very small 1 bores give more trouble in manufacture and operation than those of moderate size. Lamps of innumerable shapes and dimensions have been constructed and great variation of candle power for vari- l ous diameters obtained. There appears no reason why lamps may not be made | of any size required and of any desired candle power per inch within wide limits, 1 the only limitation appearing being that imposed by softening of glass when too many candle power per inch are produced | The general rules established regarding their operation hol.- good in so far as examined, and it is possible to predeter- mine with almost absolute exactness the voltage, current consumption and candle power of lamp when the manufacture is perfect.
 | The light produced by pure mercury gas comprises orange-yellow, lemon-yellow, green, blue, blue-violet and violet and although all shades of these colors may not be present, their absence would not l be so seriously felt were 1t not for the absence of the red. For some purposes the lack of red in the spectrum is objec- tionable. but for many uses it is a posi- 1 tive advantage.
 For shop work, draughting, reading and other work, where the eye is called upon for continued strain, the absence of red Is an advantage, for I have found light without the red is much less tiring to the eye than with 1t. It is possible to trans form some waves of this light, especially the yellow light. into red light, and thus in a measure to overcome this defect where required for general indoor illum- l ination. A moderate amount of ordinary , incandescent light interspersed with the mercury gas electric light serves to sup l ply the deficiency, and the mixture may be made most satisfactory. For ordinary street lighting purposes the mercury light | is available even without the red, and it should be noticed that this light has very l great penetrating power and seems to be | effective through greater distances than an equivalent amount of measured candle power from the ordinary incandescent | lamp. This may be due to the fact that the waves of the red light are less pene- l trating than those waves which are pres ent in the mercury light and hence the least valuable portion of the spectrum having such Illuminating effects is omit ted and the energy is practically expend- ed in the more useful portions of the | spectrum. l When 1t is considered that this light, when obtained with mercury gas, has an l efficiency at least eight times as great as that obtained by the ordinary incan- descent lamp, 1t will be appreciated that 1t has its use in places where lack of the red Is not important, for the economy of operation will much more than compen- sate for the somewhat unnatural color given to illuminated objects.
 The general subject discussed at the meeting was Methods of Illumination and Units of Light and besides MT. Hewitt's paper others were read by Dr. Clayton Halsey Sharp, Dr. Louis Bell, w. D'A. Ryan and John w. Howell.
 <><<>><<<<<<<->- terestins feature of Southern industrial development. but it is not probable that it will be undertaken in the near future outside the Birmingham district, and whether more plants will be built there Is still a matter of conjecture. Two or more are projected. The new rail mill of the Tennessee Coal. Iron and Railroad Company will add. considerably to the consumption of. Southern iron, and this will be supplemented by number of To- cal industries depending upon iron as their material. Within few years the idea of manufacturing has taken a firm hold upon the Southern people, and money seeking investment in powerfully attract ed to foundries and small industrial ven- lures. As the rule cotton manufactur- ing plants have been preferred to any other. but tendency to diversification is now noticeable. Generally speaking, Southern manufacturing is profitable. We are strongly of the opinion. however, that the best interests of the South will be found in the development of it's agricul- tural resources, and that if these are neglected for manufacturing or hampered by lack of capital because manufactur- ing investments are more attractive. Southern development will be less rapid and satisfactory than it's natural advant- ages invite A cotton crop of 10000, 900 bales would enrich the South very quick ly. and bring in its train as much devei- 1 opment in other directions as the most optimistic prophet would venture to pre- dict. s r