Lectures on Ventilation Part 4

We will allow the opening at the top for the _outlet_ of the foul(?) air to remain as before, (see Fig. 1, Lithograph plates.) This is quite an improvement; it agitates the air much more than the other, and by going and standing directly over the register, you can always get in the current of fresh warm air. But you see to what a very small portion of the room the heated air is confined, rising in one perpendicular column directly to the ceiling, and then flowing horizontally along the ceiling to the outlet. How little it disturbs the main portions of the room, especially the lower and occupied part.

I hope you will notice that this ill.u.s.trates the popular notions of ventilation. I suppose three-fourths of all the buildings in this country, or in Europe, where any attempts at artificial ventilation have been made, are thus arranged. Dr. Franklin knew better, and made a much more perfect arrangement than this. But we are probably mostly indebted to that very able and enthusiastic advocate of ventilation, Dr. Reid, for this popular opinion. The whole of the plan that he advocated is but little understood by the public. He a.s.sumed that the natural warmth of the body created an ascending current around us, and caused the breath to rise towards the ceiling, and consequently, in all artificial arrangements, it was best to endeavor to imitate this natural movement of the air. And to overcome the great practical difficulty we see here exhibited, of the fresh warm air flowing through the room, and disturbing so small a portion of it, he proposed making the whole floor one register, and thus have an ascending column over the entire room. For this purpose, the floors in the Houses of Parliament were perforated by hundreds of thousands of gimlet holes, and the whole cellar made a hot air chamber. This was a magnificent idea, and, I believe, in some few instances, where fully carried out, has given a good degree of satisfaction; but it is always difficult to adjust the opening and the pressure so as to cause an even flow over so large a surface, and at the same time to be so gentle as not to be offensive to those with whom it comes in contact. But this thorough diffusion cannot be conveniently applied in one case in a thousand. It must necessarily be always very extravagant, as it will constantly require a great amount of air to insure a thorough circulation through all parts of the room. I wish, therefore, most emphatically, to condemn all systems relying upon openings in the ceiling for the escape of the foul air, while depending upon the circulation of warmed air for obtaining the necessary additional warmth. In practice they are universally closed in winter, for the purpose of keeping warm, and as such openings have been so generally considered the _only_ ones necessary for the proper ventilation of a room, and as they had to be shut in winter, just when artificial ventilation was most necessary, it has created a very strong prejudice in the popular mind against all ventilation.

The result of the advocacy of these impracticable theories by so many able and learned men, (most physicians writing upon this subject have adopted them,) has been the shutting up of many thousands and tens of thousands, till they have smothered to death.

The ravages of consumption and the excessive infantile mortality, and the many diseases resulting from foul air poisons, are in a great measure due to the general advocacy of these false theories. As I have before said, Dr. Franklin knew better than this, and had we been contented to have followed his simple practical advice, instead of being dazzled by the splendid theories of others, thousands of our friends would now be with us who died long since for the want of fresh air.

Now, let us see how Dr. Franklin says a room ought to be ventilated.

He says, "the fresh air entering, becoming warmed and specifically lighter, is forced out into the rooms, rises by the mantel-piece to the ceiling, and spreads all over the top of the room, whence, being crowded down gradually by the stream of newly warmed air that follows and rises above it, the whole room becomes in a short time equally warmed." This is the principle upon which his celebrated Franklin stove was arranged. Now, let us see if we can arrange our little gla.s.s house so as to ill.u.s.trate this. We will first fill it with what we call our cold air, and will close the outlet at the top, and take out the fire-board. Now, as I let in the warm fresh air, it rises immediately to the top, as before, and flows across the ceiling, but as it cannot escape there, it forces the cold air down, and causes it to flow out at the fire-place. See how quickly the whole room is filled with the fresh warmed air. Ah! I see I am a little too fast--there appears to be a stratum of a foot or two, lying on the floor, that is not disturbed yet. It flows out at the top of the fire-place, and therefore does not reach to the floor. This is frequently the cause of cold feet and much discomfort. We will make the opening directly at the floor, (see Fig. 2, Lithograph plate,) and that forces all the cold air out, warming and ventilating the whole room. Here is the whole problem solved in the most beautiful and simple manner.

And you may exclaim, as you see the simplicity and perfect working of this, how came any one ever to think of anything else.

Here, again, you see the value of that most excellent and valuable of household arrangements, the open _fire-place_; even without the fire it serves a most important purpose.

[Ill.u.s.tration: Fig. 4]

[Ill.u.s.tration: Fig. 5]

[Ill.u.s.tration: Fig. 6]

We must not forget, however, that there are other circ.u.mstances in which it will not do to depend on the fire-place alone for ventilation.

Now, by leaving the fire-place open, just as it is, and the room full of warm air, we will simply change the _condition_ of the air supplied, and allow cold air to flow in at the bottom instead of the top. (See Fig.

3.) There, you see the fresh _cold_ air simply falls to the bottom and flows across the floor, without disturbing the upper part of the room at all. It acts just the reverse of the hot air let in and taken out at the top of the room. When you are ventilating a room by _opening a window_, therefore, it is often necessary to open it at the top; but remember when you are ventilating by doors and windows, (which are the great natural ventilators,) _they_ are an entire subst.i.tute for flues--flues are then of no account. All _windows_, therefore, ought to be made to _lower from the top_, and all ventilating _flues_ ought to be made to _open at the bottom_ of the room.

I have noticed another very interesting feature in regard to the circulation of liquids of different densities; for instance, suppose we fill our little room half full with salt water, and the remainder with fresh water, we will now apply a spirit lamp to the bottom of the room.

As the salt water becomes heated it rises rapidly, yet not to the top of the room, but only half-way, or to the top of the denser liquid, and then spreads across the room horizontally. Thus the salt water will keep up a rapid circulation, and may be heated almost to a boiling temperature _underneath_, and without heating or disturbing, the cold fresh water _above_. I have tried some very beautiful experiments of this kind with a number of liquids of different densities in the same vessel. Gases of different densities are probably influenced in a similar manner by the application of heat. And here we see the value of that beautiful law of the diffusion of gases, by which each gas, no matter what its density, is equally diffused in all directions through the other gases, independent of temperature.

I desire to call your attention this evening to one other distinct system of heating--I mean that very convenient, economical, cleanly and FAs.h.i.+ONABLE system of heating by direct radiation from steam-pipes.

As steam has become such a common article in all large buildings, both for power and as a convenient means of distributing heat, most large buildings are thus heated; and as a perfectly air-tight building can be very easily heated thus, and as most persons are too ignorant or too careless to provide a separate and distinct supply of fresh air simply for ventilation alone, the consequence is, that this system, thus so shamefully abused, is probably drying up more talent and killing more business men in our cities than any other system in existence.

This applies especially to the editorial rooms of nearly every one of our leading newspapers and publis.h.i.+ng houses. They use steam for driving their beautiful printing presses, and the heating and ventilation, or rather, the entire want of ventilation, in their offices, would indicate that they think that the same power that drives their presses, to do the printing so nicely, is entirely sufficient to drive them to write the original articles for the printer, and that they have no more need of _fresh air_ than their presses.

You may think that I am certainly mistaken that so intelligent a cla.s.s of the community, who are building such splendid fire-proof buildings, such perfect palaces of iron and stone and marble, as our newspaper establishments are building in New York, Philadelphia and other large cities, would never make such a blunder as to omit providing the most abundant supply of pure, fresh air to every employe in their establishments, and at all times, both in summer and winter.

Should there be any one present thus doubtful, I wish he would undertake to get any one of our enterprising newspaper establishments to publish in their paper an accurate intelligible account of their system of ventilation, ill.u.s.trating clearly the known quant.i.ty of pure, fresh air delivered within using distance of each one of the editors and employes.

I think he would soon come to the same conclusion I have, that the advice of the minister to his congregation would be very applicable to them--"Always do as I _say_, but never do as I _do_."

LECTURE III.

In my first lecture, I endeavored to show how much we were suffering from the effects of foul air, and the advantages to be gained by supplying ourselves all the time with pure air. Because we must first feel that there is something to be gained before we will make any great effort towards obtaining a given result.

In my second lecture we considered the general principles governing the circulation of air, the courses of its movements, the manner of the action of heat upon different kinds of substances, which creates a constant, ceaseless motion of the air, in all places, from the minutest corked bottle to the vast currents that sweep over the face of the earth.

Now, having learned the necessity for pure, fresh air, and studied the general laws governing its circulation, let us apply these principles to every-day life. To every-_day_ life? I should say every-_hour_ life--nay, every _moment_ of our lives; for twenty times every minute of our entire life, from the cradle to the grave, do we breathe what ought to be pure air. Is it always pure?

If we breathe one single breath, in the entire day, of _impure_ air, it will weaken us, deduct from our capacity to attend to our daily duties, and shorten our lives, in exact mathematical proportion to the amount of impurity in that one single breath. Now, we breathe twenty times every minute, twelve hundred times every hour, twenty-eight thousand times every day, and nothing but absolute and perfectly pure air answers the exact requirements of perfect health.

Well, you may ask, at first thought, if fresh air is such a panacea for all evils, and there is such an abundance of it out of doors, why not breathe it, and always enjoy perfect health?

Think one moment. I eat my breakfast in the morning, generally refreshed by a night of good sound sleep, (for I sleep with my windows open.) Immediately after breakfast, I enter the cars to come to the city. What a smell comes from the car as the door is opened! and unless I wish to incur the displeasure, or provoke the indignation, of almost every pa.s.senger, by opening a window, I am obliged to sit in that foul, offensive atmosphere, and breathe the poisonous exhalations from my own lungs, and that from dozens of others, some of them, it may be, badly diseased, (most persons' lungs _are diseased_ in this country, from breathing foul air, and many other diseases besides consumption are produced thereby.)

Thus, in one half hour, I have inhaled six hundred times of this foul and poisonous air, and the blood has carried it to every portion of my body, so that my entire system is completely saturated, poisoned, yes, thoroughly poisoned by it, from the crown of my head to the soles of my feet.

And thus is the day commenced. Your blood is thoroughly poisoned before your breakfast is digested; for your breakfast will no more digest without pure air than the coal in your stove will burn without it. You are subjected to headache, dyspepsia, and a half dozen other aches and pains, and are tired out long before night. And thus you are killed long before you would die if you breathed pure air only.

And am I relieved from the difficulty when I arrive in the city?

Start to-morrow morning at the Delaware River, on Arch or Walnut Streets, or any other street, and go to the Schuylkill. Inquire of every individual, in office, store, dwelling or factory, if he knows whether he had pure air to breathe all day, or whether he can tell you, with any degree of accuracy, how pure the air was in the room he occupied for any hour of that day.

I fully believe there is not one in ten--no, not one in a hundred--of the most intelligent men in that entire street, doctor, lawyer, architect, or any other, that can give you an accurate account of the condition of the air breathed during any one hour of the day. That is not all. There is scarcely one in a hundred that can satisfy you, by an intelligent description, of the means used for providing it:

First--a.s.suming the air outside to be pure, that there was a constant, positive and sufficient supply of that outside air introduced.

Secondly--That that pure air was not deteriorated by overheating, or contaminated by being mixed with the poisonous gases of the burning coal.

Thirdly--That there was sufficient moisture added to it to compensate for its increased capacity for moisture, due to its expansion by the additional heat given to it, (which is a very important thing.)

Fourthly--That there was any accurate, positive means provided for insuring the fresh air to be brought within reach of the lungs of those for whom it was intended.

And, lastly--That there was a positive means provided for the removal of all the poisoned air thrown from the lungs, so that none could possibly be _re-breathed_.

No; you will find them in close, unventilated offices, in close factories, in almost _air-tight_ dwellings. In the large stores they do better.

The air is very commonly overheated, it is often mixed with impurities, and very seldom supplied with a proper amount of additional moisture.

The air is often so dry, that in a few minutes' conversation the linings of the air-pa.s.sages to your lungs become parched and husky, producing irritation and a feverish condition of the system. And even in this room, to-night, do you see any opening at your feet, connected with a heated flue, for drawing the foul air from the floor as fast as thrown from your lungs? I believe there is not a square inch provided for that purpose.

Or, do you see any escape immediately above the gas-lights, for carrying off the burned air while hot enough to escape? Not one. There are two or three openings, I think, in the back part of the room, just at the ceiling, but for your breath to get there, it must rise and pa.s.s by the zone of respiration, and much of it be again re-breathed; and the products of combustion, as we have seen, would cool sufficiently to fall to the floor long before they reached that point.

I take the liberty of calling your attention to this with more freedom, because it does not indicate any special inattention on the part of the Managers. It is not an exceptional case, but it is the rule. It is the popular opinion of the proper means of ventilation.

Go with me, if you please, to that magnificent building, completed but a few years since, at a cost of half a million of dollars, and given by its n.o.ble and generous founder to the city of New York. You will notice, inscribed above the entrance, cut in the solid stone, "To the Arts and Sciences." Look in this reading-room--perhaps the most useful and most appreciated of any public reading-room in the United States. See the large numbers of honest, industrious mechanics, s.n.a.t.c.hing an hour from their labors, to look over the current literature of the day. Here, certainly, we shall find the most perfect arrangement for heating and ventilation that our knowledge of the arts and sciences could suggest. Let us see the arrangements for bringing in the fresh air, for warming it in cold weather, and for removing the foul air.

What! no provision for a regular supply of fresh air? Not one foot, not one inch--neither are there any regular flues for the removal of the foul air. And this most remarkable condition of things is but repeated in the magnificent hotels, marble palaces used as offices, and in many of the new and splendid colleges; and, we might almost say, in all other buildings throughout the length and breadth of our land.

Thus you see how difficult it is for one to mingle freely in the society of his fellow-men, under existing circ.u.mstances, without being subjected to being poisoned by foul air. In going from here to my home, to-night, I shall have to ride in those cars, the air of which I dread more than I ever dreaded the small-pox or cholera. I have been in hospitals where I have seen much of both. They may slay their thousands, but foul air its tens of thousands. And it is only when I get to my room, where I shall probably sleep to-night with two windows well open, allowing the un.o.bstructed breezes of half a mile of open country to sweep through my chamber, that I shall feel entirely secure from the contaminating influences of foul air, and enjoy to its full extent the greatest of G.o.d's temporal blessings to man--_pure air_.

I have no new patent idea to present to you, which shall secure to you at all times perfectly pure air, without any further trouble on your part. There are no two const.i.tutions precisely alike, any more than there are two human faces, or two handwritings, and there are no two hours in our entire life in which all the physical conditions of our body are precisely the same. It would be just as absurd, therefore, to go to a ventilating establishment, and tell the proprietor to ventilate your house or office, and pay the bill when it came in, and content yourself by saying: "Well, I am glad this ventilating business is done with. I have got my house ventilated, and the bills paid, and I am glad I am _through_ with that vexatious business." I say this would be just as absurd as it would be, in case you had some pain or ache, to go to your doctor and get some medicine, and therewith content yourself, and say: "Well, I am glad this doctoring business is over with; I have been dreading it all my life. I have been to the doctor's at last, have been doctored, and got my medicine and paid my bill, and so I am through with that vexatious business."

No--you must first feel that fresh air is worth taking some trouble to obtain. You must then make it a _study how_ to obtain it without _chilling_ or _overheating_ your body, in winter and in summer, at night and in the day time, when you are lying down and when you are sitting up, before eating and after eating, before exercising, while exercising, and after exercising--when you are well and when you are sick, when you are alone and when you are in the crowded cars, or in a crowded room, in wet weather and in dry, and for the ever varying changes of the external atmosphere--all these conditions require separate and intelligent thought.

In summer we depend almost exclusively on the natural movements of the air. To cause the air to _move_ is then the great matter. We must then remember that the great ma.s.ses of air move horizontally, not perpendicularly. Of course, there are many little disturbing influences, but I mean the great ma.s.s of the air moves over the surface of the earth in horizontal strata. You can see this by the smoke of the locomotive on the prairie, which can be seen sometimes for twenty or thirty miles, stretching along just above the horizon. All _flues_, therefore, are of little account in summer. We must depend on open doors and windows. Suppose you wish to ventilate your room in the morning, the air outside having become a little warmer than the air inside, and the upper parts of the window only lowered: the warmer air would flow across the top of the room, leaving the air undisturbed in the lower and colder part. In this case, the window should be raised from the bottom, or a door opened that would afford an escape for the air.

But again, suppose this same room to want ventilating in the evening.

The room has become warm through the day, and the outside evening air is cooler than the room, and then, if you raise the windows from the bottom only, the cooler air will flow across the bottom of the room, leaving the upper part undisturbed and foul.