The Air We Breathe

I have an old book on my shelf that came to me by way of my friend Paul Yunnie. Paul lives in England and is Chairman of the ASHRAE Historical Committee. I time-travel with him.

I ran into Paul at the big ISH fair in Frankfurt one year. We had a chance to drink a coffee and catch up, and that reminded me of the old book that’s on my shelf. Paul had put me on to the bookseller in London some years back, and I think I paid about three-hundred bucks for this one because of its age and good condition. The title of the book is Theory and Practice of Ventilation and the author, David Boswell Reid, M.D, is very famous, at least as far as heating history goes. He was a medical doctor and a pioneer engineer, and in 1844, he cared about people.

The book is in remarkably good shape and I bring it down off the shelf from time to time to hold it and page through it, and to wonder how many owned it before it came to be on my shelf. I wonder about the systems they may have designed from this book.

The title of Chapter IV is Slave Ships. There are pen and ink drawings of human beings stacked like cordwood below decks. This was an engineering concern at the time – how do you deal with the air on slave ships? What follows are Doctor Reid’s thoughts, offered from the grave, to the engineers of his time. Listen.

‘It might be expedient that vessels sent to capture slaves be provided with a portable ventilator, which might prove useful in removing the atmosphere before the sailors enter below deck, when it is in an extreme condition, and also when they may have to be conveyed for a considerable distance before they reach the shore.

‘In these ships, the Negroes are stowed between the decks, which are seldom more than two or three feet, and sometimes not more than eighteen inches in height.

‘In this condition, men, women, and children, perfectly naked, and, in many cases, the women either in a state of pregnancy or carrying their children of from four- to twelve-months old, are conveyed to their wretched holds. In these dungeons of misery, they are packed together so close, that, in some instances, they are obliged to lie on their sides, and, from the small space between the decks, are unable even to sit erect.

‘It is computed that no fewer than three thousand slaves are annually thrown overboard. If the captain of the vessel apprehends that his supply of water will not hold out till the end of the voyage, he meets his difficulty by devoting to the waves the surplus of his wretched cargo of human beings, retaining only those for whom he calculates that he has a sufficiency. On one occasion, on this account, one hundred and thirty-two were destroyed.”

And he goes on for several more pages, describing the conditions on those horrible ships and how to best protect the sailors from the miasma. The slaves he merely pities. Imagine you were an engineer then. You may have owned this book in my hands. Imagine living then.

Doctor Reid goes on to write about convict ships, which regularly traveled from England to Australia in those days. He explains what’s required for good shipboard ventilation (his words):

  1. A regulated ingress of fresh air
  2. A vitiated air-channel from each deck, discharging the bad air without sending it previously, as the only supply, to other decks.
  3. The reunion of all the discharges in a central escape, controllable by a valve, so as to be regulated to any degree that the numbers in the ship, the state of the atmosphere, and other circumstances, may render necessary.
  4. The introduction of a screw, or of a windmill ventilator, in the escape, that ventilation may be insured in all states of the atmosphere. In sultry and oppressive nights, one of the convicts turning the windmill ventilator would give great relief to all.

And he continues, “I examined very particularly the movement of the currents on one occasion, from the time the men went to rest until they rose next morning. Those nearest the ingress of the air on the lower-deck had good air, but rather in excess – those a little farther on were comfortable – the heat of the air warmed below by the respiration of the men, and by their bodies generally, gave it an ascensional power which enabled it to exclude fresh air from the deck above. Those above accordingly respired. All, except a few, respired bad air.’

And he goes on in his book to write about ventilation in the House of Commons, and in schools of that time, and of the dangers of carbonic acid build-up in graveyards, particularly in mass graves. And of how the graves would pollute the water supply. And he makes good, solid engineering recommendations, and all of this makes me swoon when I think of how life must have been in those days. And it’s really not that long ago. It really isn’t.

I was on a bus in Illinois with 30 other people not long ago when the ventilation system broke down. We sat in bumper-to-bumper traffic just outside of Chicago and the windows fogged over and everyone sat very still and there was nothing the driver could do for us because windows on buses no longer open, nor do windows on trains, or in most of our newer buildings. I thought of how much we depend on our mechanical systems for comfort, and for the very air we breathe.

And I thought about Doctor Reid.

Dan Holohan

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