Electric dissipation of fogs

454

Notes and Comments. ELECTRIC

DISSIPATION

[J. F. L.

OF FOGS.

T h e dispelling1 of fogs by m e a n s of electric c u r r e n t s is exciting a g o o d deal of i n t e r e s t a m o n g leading physicists of the world. I t is possible by the use of electricity to rid the city of L o n d o n or New Y o r k h a r b o r or San F r a n c i s c o h a r b o r or any o t h e r n e i g h b o r h o o d of t h e heaviest fog.

The

only question is the cost. It m a y be t o o great, and this is what a commission is trying to ascertain at the instance of the city of L o n d o n . T h e rep o r t is looked forward to with much interest. Sir O l i v e r J . Lodge, one of the f o r e m o s t of British physicists, is giving this subject p r o f o u n d t h o u g h t , which is itself p r o o f of the i m p o r t a n c e of the w o r k and of the probability of the successful solution of the problem. His latest patent, just granted. provides for a comparatively simple electrical apparatus, consisting of "a c o m b i n a t i o n of high ~)otential rectifiers a r r a n g e d in quadrilateral g r o u p s of four, or multiples of four in sucb~ a way that, instead of the reverse pulses of the a l t e r n a t i n g c u r r e n t supply b e i n g suppressed or n o n e x i s t e n t as at present, they are redressed to form the positive a n d negative d i s c h a r g i n g s t r e a m s required for deposit purposes." In o t h e r words, the a l t e r n a t i n g c u r r e n t is used, but the pulse is all in one direction. T h e p r o p e r t y of the electric discharge of causing the coalescent deposit of m a t t e r s suspended in a gaseous medium has not come into general practical use on account of the difficulties a t t e n d a n t on the use of the statical electrical apparatus, this class of a p p a r a t u s b e i n g t o o delicate and easily upset for use on an extensive scale, to again quote from Sir O l i v e r ' s patent papers. T h e r e is n o t h i n g new in the k n o w l e d g e of the general principle involved in all fog-dispelling apparatus. T h e direct c u r r e n t passing t h r o u g h the a t m o s p h e r e provides, in the form of electrons, the n e c e s s a r y nucleus about which the particles of m o i s t u r e collect until they constitute drops of rain. T o dispel the L o n d o n fogs, for example t h e apparatus would be stationed at different points a b o u t the city to project t h e i r currents t h r o u g h the a t m o s p h e r e until the fogl has precipitated as rain. Electrical engineers agree that the cost of such o p e r a t i o n s would probably be great, m e a s u r e d in equipment and maintenance, as well as in h o r s e p o w e r required. I t would m e a n the e s t a b l i s h m e n t of large electric power stations. Possibly such stations m i g h t dispose of t h e i r power to financial a d v a n t a g e d u r i n g days w h e n t h e i r services are not needed for ridding the city of fog. But the cost of alleviating this moisture and h i n d r a n c e to business would be considerable, no m a t t e r how economically the electric plants m i g h t be managed.. Y e t in c o n s i d e r i n g the cost, it must be with relation to the good accomplished in the health and c o m f o r t of the community, as well as to business. A L o n d o n fog costs a g o o d deal of money. So does a fog in such a h a r b o r as New York. It holds up tho routine of business, which is expensive. T h u s while it m i g h t cost a great deal of money, yet c o m p a r e d with the financial saving by p r e v e n t i n g the h o l d i n g up of business, and with" the general public benefit, the expense m i g h t be relatively small, as is frequently the case in the m a t t e r of large public e x p e n d i t u r e s . - -

~cientit~c American Supplement.