The daily morning journal and courier., 1895-03-02
LECTURE ON ELECTRICITY.
lTR. WURTS OF THE WESTINGHOUS USE
 COMPANY SPEAKS or

'Lightning Arresters"-Highly Interesting
 Experlments-SOme Facts About Elec-
 tricity--A Big Audience, One of the Largest
 Ever Seen in North Shelf. Hall.
 The fifth in the course of Mechanics lectures was delivered last evening in North Sheffield hall by MT. Alexander J. Wurts 'SS s., of Pittsburg, Pa, The subject of the lecture was Lightning Arresters." MT Wurts is an authority on this subject, and has invented a number of arresters intended for pro lection of electric lighting and power currents from direct and indirect dam age from lightning discharges
 Tn his lecture MT. Wurts said that early telegraph operators noticed that during thunder storm their apparatus was frequently damaged on account of the current penetrating the insulation, and that this was done by the current jumping from the wires or terminals the lecturer showed by experiments. At first it was thought that the wires were struck by lightning, and even to-day many think that this is true, but such is not the case. The atmos- phere is all the time heavily charged with electricity and wires strung over head become, so to speak, a part of the atmosphere and this cannot be in the strict sense of the word struck by light ming. It is this fact of the wires being a sort of part of the atmosphere which causes them to transmit to the offices and apparatus any undue charge of electricity. Tn those early days the apparatus used was not very expensive and there was no necessity of exten- sive precautions against injury to in- struments, but at the present day mill lions of dollars are invested in electrical appliances and 1t becomes matter of dollars and cents when these mishaps occur. So, much science and labor has been used in devlsing a method of arr resting the destructive current. In the earlier history of electricity lightning arresters were attached to the wires, | but these generally proved inefficient. | The reason of this was that electricity | travels over a wire in waves much | the same as water when set in | motion circles and surges, and unless the arresters are attached at the crest | of these electric waves, they will al- ways prove ineffective and as formerly | only one or two arersters were used on | a line they hardly ever happened to be at the crest of the electric wave, which is continually changing. Now the arresters are more numerous, sev-l eral being attahced to each line, andl the chance of catching the surge right is increased. MT. Wurts has devoted much time to experimenting to find | some sort of arrester which would carry off the disruptive discharges and not at | the same time take the dynamic current | off on a short circuit. After much ex- pertinent he found that zinc, bismuth, antimony and mercury would take off this disruptive current, but would not take the dynamic current, as non-arcic vapors were formed which would not admit the dynamic current. Lightning arresters certainly offer opportunities for discharge, but when this takes with It the dynamic current the apparatus Is destroyed and power is lost. A sys- -em of coils not only protects liberal distribution of line arresters, but offers he only practical means of protecting widely distributed apparatus, as on rolley and lighting systems. The arr 'esters fail to protect in all cases be- 'ause of the continual shifting high md low pressure currents, or in other words for lack of sufficient mum ,er of line arresters, because insulation s defective, and because lightning ar esters are not properly installed,
 The lecture was most interesting and being illustrated ait all joints by experiments and charts.
 The wires of the Winchester avenue rolley line had been tapped and a urrent of 1000 volts, which was neces- ary to carry out the experiments, was btained. Mir. Wurts is member of he Westinghouse Electric and Manu-I acturing company of Pittsburg and as been awarded the John Scott legacy ledal by the Franklin Institute of the tate of Pennsylvania on account of is important inventions in electrical machines and apparatus The hall last evening was crowded 9 it's utmost capacity, even all the -anding room being taken up and many yere unable to get in at all