MEASURING AIR POLUTION.

Pahiatua Herald, Volume XXVII, Issue 31362, 18 January 1923, Page 7

MEASURING AIR POLUTION.

The importance of maintaining the purity of the atmosphere of towns was never more widely recognised than it is to-day. Much .lias been written, about the subject from the standpoint of public health, and also from that of preserving buildings from decay. In, order to put the subject on a scientific basis a special committee attached to the Rritish Meteorological Office lias, during relent years carried out a long series of experiments. An instrument was devised for actually recording the amount of smoke and dirt in the air throughout, the day and night. This instrument consisted of a piece of filter paper through a portion of which air was drawn for about ten minutes a't a time. At the end of each ten minutes a fresh piece of paper was moved to the orifice and another charge taken. The depth of the shadow thus produced formed a measure of the amount of dirt in the atmosphere from the factory chimney. Attention is now being given hv Rritish Public Health Authorities to the question of how, far gas and electricity can he made to replace the open coal fire, and! as to tlie prospects of producing a smokeless fuel from coal at a low cost.