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LECTURES ON VENTILATION:

  BEING A COURSE DELIVERED IN THE FRANKLIN INSTITUTE, OF PHILADELPHIA,
  DURING THE WINTER OF 1866-67.


BY LEWIS W. LEEDS,

    Special Agent of the Quartermaster-General, for the Ventilation
    of Government Hospitals during the War; and Consulting Engineer
    of Ventilation and Heating for the U. S. Treasury Department.


=Man's own breath is his greatest enemy.=


  NEW YORK:
  JOHN WILEY & SON, PUBLISHERS,
  2 Clinton Hall, Astor Place.
  1869.



  Entered according to Act of Congress, in the year 1868, by
  LEWIS W. LEEDS,
  In the Clerk's Office of the District Court of the United
  States for the Southern District of New York.


  New York Printing Company,
  81, 83, _and_ 85 _Centre Street_,
  New York.




PREFACE.


These Lectures were not originally written with any view to their
publication; but as they were afterwards requested for publication in the
Journal of the Franklin Institute, and there attracted very favorable
notice, I believed the rapidly increasing interest in the subject of
ventilation would enable the publishers to sell a sufficient number
to pay the expense of their publication; and, if so, that this very
spirit of inquiry which would lead to the perusal of even so small a
work, might be one step forward towards that much-needed more general
education on this important subject.

It was not my desire to give an elaborate treatise on the subject of
ventilation. I believed a few general principles, illustrated in a
familiar way, would be much more likely to be read; and, I hoped, would
act as seed-grain in commencing the growth of an inquiry which, when once
started in the right direction, would soon discover the condition of the
air we breathe to be of so much importance that the investigation would
be eagerly pursued.

                                                               L. W. L.




CONTENTS.


LECTURE I.

    Philadelphia a healthy city--Owing to the superior ventilation
    of its houses--But the theory of ventilation still imperfectly
    understood--About forty per cent. of all deaths due to foul
    air--The death rate for 1865--Expense of unnecessary sickness--In
    London--In Massachusetts--In New York--In Philadelphia--Consumption
    the result of breathing impure air--Entirely preventable--Infantile
    mortality--Report on warming and ventilating the Capitol--Copies
    of various tables therefrom--Carbonic acid taken as the
    test, but not infallible--The uniform purity of the external
    atmosphere--Illustrated by the city of Manchester--Overflowed
    lands unhealthy--Air of Paris, London and other cities--Carbonic
    acid in houses--Here we find the curse of foul air--Our own
    breath is our greatest enemy--Scavengers more healthy than
    factory operatives--Wonderful cures of consumption by placing
    the patients in cow stables--City buildings prevent ventilation,
    consequently are unhealthy--The air from the filthiest street
    more wholesome than close bed-room air--Unfortunate prejudice
    against night air--Dr. Franklin's opinion of night air--Compared
    with the instructions of the Board of Health, 1866--Sleeping with
    open windows--Fire not objectionable--A small room ventilated is
    better than a large room not ventilated--Illustration--Fresh
    air at night prevents cholera--Illustrated by New York
    workhouse--Dr. Hamilton's report--Night air just as healthy
    as day air--Candle extinguished by the breath--The breath falls
    instead of rises--Children near the floor killed first--Physicians'
    certificates do not state "killed by foul air"--Open fire-places
    are excellent ventilators--All fire-boards should be used for
    kindling wood--Illustration showing when ceiling ventilation
    is necessary.

                                                                 PAGE 3


LECTURE II.

    The effect produced by heat upon the movements of air--Air
    a real substance--Exerts a pressure of fifteen tons on an
    ordinary sized man--It cannot be moved without the expenditure
    of power--The sun's rays the great moving power--They pass
    through the forty-five miles of atmosphere without heating it,
    and heat the solid substances of the earth's surface--Experiments
