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Transactions Texas Academy of Science. 
charged directly into streams, but should he run into the sewers or sep- 
arately pnrified. 
While not nsnally considered a part of the work of the sanitary engi- 
neer the matter of good street surfaces has an important hearing upon 
the health of a community. Good, smooth surfaces that will shed water 
readily and that will not absorb and retain moisture and organic matter 
subject to decay are matters that alfect the health of every passer by, the 
construction of which comes directly under the supervision of the civil 
engineer. So also the proper heating and ventilation of buildings con- 
stitute a branch of engineering that lies on the border land that separates 
civil from mechanical engineering, and which are important factors as 
regards the health of a community. It is certain that the crowding of 
many school children into poorly heated, poorly lighted, poorly venti- 
lated rooms for several hours each day often results in weakened consti- 
tutions, ending finally in disease which is charged to overstudy. In this 
case, as in many others, we are prone to accept the first explanation that 
occurs to us, instead of looking for the real cause of the trouble. 
It is no easy matter to compute the money value of a proper saintary 
condition in a community, but if we return to the figures given for the 
saving of life from typhoid fever alone in Chicago, for the years 1894, 
1895 and 1896, due to the change in the water supply, we shall have 
enough to set us thinking. As I told you an average of 1280 lives per 
annum was probably saved to that city during those three years. ISTow, 
place the money value of each life at $5000, this being the amount that 
courts of justice have several times allowed in cases where some of our 
cities have been sued for negligence leading to loss of life, and we shall 
have the surprising figures of $6,400,000. Taking the death rate at 
Philadelphia, as given a while ago, as probably showing the same propor- 
tion of deaths to total cases — namely, one-tenth of the cases fatal — we 
should probably have 11,500 cases in Chicago annually that would have 
survived for the 1280 that would probably have died, and if the expense 
of doctors’ bills and the financial loss due to illness be placed at $300 
per case we should have an additional sum of $3,450,000, making a 
grand total of $9,850,000 annually saved to the residents of the city, as 
regards this one disease, which was effected by the change in the water 
supply. ISTow capitalize this at the very high rate of ten per cent, per 
annum to allow for a sinking fund for repairs and you get $98,500,000 
that Chicago would have been justified in expending for the change, 
when as a matter of fact the actual cost was probably only a small frac- 
tion of this amount. 
While the foregoing does not by any means cover the field of the work 
of the sanitary engineer in its relation to the health of the public, the 
matters mentioned will suffice to show that the relation is an important 
