Show WHY ELECTRIC HISS due to thenea ted carbon points evaporating ora 1191 prof sylvus Syl thompson has ben been ansbe answering r 1 ng a question which has of auxt puzzled puzzle d the public the are arc light proceeds from the points of two little carbon rods as large as ones little finger prof thomp thompson on explains what is the state of the carbon when the lamp is throwing out its light he says reports the pittsburgh dispatch that the carbon is sometimes actually mel melting tinga a thing that was until recently thought impossible moreover he says says that when a light is hissing the liquid carbon is really boiling in ordinary combustion the state of the are arc crater crater is such that the solid carbon below is covered with a layer or film of liquid carbon just boiling or e evaporating rap orating off when hissing takes place the new state of things is set up ile he says if you watch a short hissing are arc you will see a column col lumn of light concentrating itself itzell on a narrow spot and the spot keeps moving about and is very unstable in position as well as in the amount of light it gives out the crater surface after the are arc has been hissing is found to be lite literally rally honeycombed when the are arc is hissing you can see little bits erupted out and the hissing seems to be compared to the hissing which takes place in boiling water there is in fact exactly the same kind of difference between the silent arc and the hissing vre as between quiet evaporation and a noisy boiling |