JANUAET 6, 1911] 



SCIENCE 



17 



With your permission I shall address 

 my remarks to certain specific matters 

 which have come under my observation in 

 Greater New York, and to which I have 

 given special study. No doubt these mat- 

 ters have already been considered in some 

 of your conferences, but the public expres- 

 sion of the independent point of view of 

 one unhampered by official ties may serve 

 one good purpose, namely, of provoking 

 discussion, which can be made profitable. 



The consideration of the air of cities 

 involves not only the principles of ventila- 

 tion, which will not be considered here, 

 but the construction of the streets, means 

 of transportation, the disposition of wastes, 

 and the handling of the more unusual con- 

 taminants, which vary with conditions. 



There are more than 2,000,000 miles of 

 public roads in the United States outside 

 of municipalities. These roads in many 

 cases are essentially the same as we find in 

 the outskirts of our larger cities, and are 

 the roads of the smaller towns. The town 

 roads are traveled very much more, so the 

 actual facts at hand for the average road 

 are applicable to the town roads, for which 

 no satisfactory data are available. Cush- 

 man has calculated that 500,000 tons of 

 dust are raised on the public roads per day, 

 or, taking 100 dry days in the year, 50,- 

 000,000 tons of material are taken from 

 places where it is needed and placed where 

 it is undesirable by the movement of ordi- 

 nary vehicles. A discussion of economic 

 principles of road conservation is not ger- 

 mane to our subject. Suffice it to say that 

 the modern motor-driven vehicle is not a 

 dust maker, but a dust raiser. 



The dust problem did not begin with the intro- 

 duction of the automobile, although it has un- 

 doubtedly been accentuated by this mode of travel. 

 There are sections of our country at the present 

 time where the roads have been rendered prac- 

 tically dustless, and neither horse-drawn vehicles 

 n.or automobiles can now deposit the dirt of the 



highways in the gardens and houses of abutting 

 property owners. This condition of aifairs did not 

 exist before the introduction of the automobile, 

 but has been arrived at in answer to the demand 

 which has followed its use. In short, there are 

 many suburban communities in which life to-day 

 is far more agreeable, pleasurable and possible 

 than it was before automobiles came into use. 



Why may we not have this in every city ? 



Aside from the personal discomfort from 

 flying particles of solid material, whatever 

 be its nature, these particles are the bac- 

 terial aeroplanes. Sedgwick has shown 

 that 10 liters of air taken five feet above 

 a macadamized street in a dust storm may 

 contain as many as 200,000 micro- 

 organisms. 



There is a natural fouling of the street surface 

 and an unnatural fouling. The natural comes 

 from excrement from animals,^ detritus from wear 

 of pavements, soot and dust from the air, leaves 

 from the shade trees, and the grindings from tires 

 and shoes. The unnatural, or, rather, avoidable 

 causes are: refuse thrown or swept upon the 

 streets from buildings, refuse thrown by careless 

 users and refuse spilled from vehicles carrying 

 material through the streets. The latter causes 

 are supposed to be prevented by the operation of 

 ordinances which are honored in the breach, and 

 these causes result in the greater cost of cleaning,' 

 as the sweeper has considerable work in collecting 

 litter before attacking the dirt, and the material 

 is bulky.* 



Commissioner Edwards, of New York 

 City, says in Municipal Chemistry that 



" One thousand horses will, in every working 

 day of eight hours, deposit about 500 gallons of 

 urine and 10 tons of dung upon the pavements. 

 " On the Utilization of Stable Waste," see Birch- 

 more, Journal of the Society of Chemical Indttstry, 

 1900, Vol. 19, p. 118. 



° For cleaning all the boroughs in Greater New 

 York of garbage, ashes, refuse and street sweep- 

 ings, the Board of Estimate and Apportionment 

 allowed an appropriation of $7,418,299.20 for 

 1909, and this amount was divided among the 

 boroughs, Manhattan receiving $4,230,441.70; The 

 Bronx, $560,371.30; Brooklyn, $2,492,481.20, and 

 for general administration, $135,005. 



■■ Very, " Municipal Chemistry," McGraw-Hill 

 Pub. Co., 1910, p. 243. 



