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Ben Franklin

Daylight Saving Time (False)


Franklin is often given credit for inventing Daylight Saving Time. He did write a satirical piece, published (in French) in the April 26, 1784 edition of the Journal de Paris, in which he claims credit for discovering the fact that the sun begins shining from the moment it rises, something that the locals, who sleep till noon, would never have means of knowing. To save on wasteful candles, Franklin recommends taxing people who use shutters, and ringing bells every morning at sunup to force people to adjust their days according to the availability of sunlight.

The text of this letter is translated below:

Letter to the Editor of the Journal of Paris, April 26, 1784

To the Authors of the Journal


You often entertain us with accounts of new discoveries. Permit me to communicate to the public through your paper, one that has been late made by myself, and which I conceive may be of great utility.

I was the other evening in a grand company, where the new lamp of Messrs. Quinquet and Lange was introduced, and much admired for its splendor; but a general enquiry was made, whether the oil it consumed was not in proportion to the light it afforded, in which case there would be no saving in the use of it. No one present could satisfy us in this point, which all agreed ought to be known, it being a very desireable thing to lessen, if possible, the expence of lighting our apartments, when every other article of family expence was so much augmented.

I was much pleased to see this general concern for economy; for I love economy exceedingly.

I went home, and to bed, three or four hours after midnight, with my head full of the subject. An accidental sudden noise waked me about six in the morning, when I was surprized to find my room filled with light; and I imagined at first that a number of those lamps had been brought into it; but rubbing my eyes I perceived the light came in at the windows. I got up and looked out to see what might be the occasion of it, when I saw the sun just rising above the horizon, from whence he poured his rays plentifully into my chamber, my domestic having negligently omitted the preceding night to close the shutters.

I looked at my watch, which goes very well, and found that it was but six o'clock; and still thinking it something extraordinary that the sun should rise so early, I looked into the almanack, where I found it to be the hour given for his rising on that day. I looked forward too, and found he was to rise still earlier every day till towards the end of June, and that at no time in the year he retarded his rising so long as till eight o'clock. Your readers, who with me have never seen any signs of sun-shine before noon, and seldom regard the astronomical part of the almanack, will be as much astonished as I was, when they hear of his rising so early; and especially when I assure them that he gives light as soon as he rises; I am convinced of this. I am certain of my fact. One cannot be more certain of any fact. I saw it with my own eyes. And having repeated this observation the three following mornings, I found always precisely the same result.

Yet so it happens, that when I speak of this discovery to others, I can easily perceive by their countenances, though they forbear expressing it in words, that they do not quite believe me. One indeed, who is a learned natural philosopher, has assured me that I must certainly be mistaken as to the circumstance of the light coming into my room; for it being well known, as he says, that there could be no light abroad at that hour, it follows that none could enter from without; and that of consequence my windows being accidentally left open, instead of letting in the light, had only served to let out the darkness; and he used many ingenious arguments to shew me how I might by that means have been deceived. I own that he puzzled me a little, but he did not satisfy me; and the subsequent observations I made, as above-mentioned, confirmed me in my first opinion.

This event has given rise in my mind to several serious and important reflections. I considered that if I had not been awakened so early that morning, I should have slept six hours longer by the light of the sun, and in exchange have lived six hours the following night by candle light; and the latter being a much more expensive light than the former, my love of oeconomy induced me to muster up what little arithmetic I was master of, and to make some calculations, which I shall give you, after observing that utility is, in my opinion, the test of value in matters of invention, and that a discovery which can be applied to no use, or is not good for something, is good for nothing.

I took for the basis of my calculation the supposition that there are 100,000 families in Paris, and that these families consume in the night half a pound of bougies, or candles, per hour. I think this a moderate allowance, taking one family with another; for though I believe some consume less, I know that many consume a great deal more. Then estimating seven hours per day, as the medium quantity between the time of the sun's rising and ours, he rising during the six following months from six to eight hours before noon; and there being seven hours of course per night in which we burn candles, the account will stand thus:

In the six months between the 20th of March and the 20th of September, there are Nights:183
Hours of each night in which we burn candles:7
Multiplication gives us for the total number of hours:1,281
These 1281 hours, multiplied by 1000,000, the number of families, give:128,1000,000
One hundred twenty-eight millions and one hundred thousand hours, spent at Paris by candle-light, which at half a pound of wax and tallow per hour, gives the weight of:64,050,000
Sixty-four millions and fifty thousand of pounds, which, estimating the whole at the medium price of thirty sols the pound, makes the sum of ninety-six millions and seventy-five thousand livres tournois:96,075,000

An immense sum! that the city of Paris might save every year, only by the oeconomy of using sun-shine instead of candles.

If it should be said that people are apt to be obstinately attached to old customs, and that it will be difficult to induce them to rise before noon, consequently my discovery can be of but little use; I answer, nil desperandum, I believe all who have common sense, as soon as they have have learnt from this paper that it is day-light when the sun rises, will contrive to rise with him; and to compel the rest, I would propose the following regulations:

First. Let a tax be laid of a louis per window, on every window that is provided with shutters to keep out the light of the sun.

Second. Let the same salutary operation of police be made use of to prevent our burning candles that inclined us last winter to be more oeconomical in burning wood; that is, let guards be placed in the shops of all the wax and tallow chandlers, and no family permitted to be supplied with more than one pound of candles per week.

Third. Let guards also be posted to stop all the coaches, &c. that would pass the streets after sun-set, except those of physicians, surgeons, and midwives.

Fourth. Every morning, as soon as the sun rises, let all the bells in every church be set ringing; and if that is not sufficient, let cannon be fired in every street, to wake the sluggards effectually, and make them open their eyes to see their true interest.

All the difficulty will be in the first two or three days; after which the reformation will be as natural and easy, as the present irregularity: for ce n'est que le premier pas qui coute. Oblige a man to rise at four in the morning, and it is more than probably he shall go willingly to bed at eight in the evening; and having had eight hours sleep, he will rise more willingly at four the morning following.

But this sum of ninety-six millions and seventy-five thousand livres, is not the whole of what may be saved by my oeconomical project. You may observe, that I have calculated upon only one-half of the year, and much may be saved in the other, though the days are shorter. Besides the immense flock of wax and tallow left unconsumed during the summer, will probably make candles much cheaper for the ensuing winter, and continue cheaper as long as the proposed reformation shall be supported.

For the great benefit of this dixcovery, thus freely communicated and bestowed by me on the public, I demand neither place, pension, exclusive privilege, or any other reward whatever. I expect only to have the honour of it. And yet I know there are little envious minds who will, as usual, deny me this, and say that my invention was known to the antients, and perhaps they may bring passages out of old books in proof if it. I will not dispute with these people that the antients might know the sun would rise at certain hours; they possibly had, as we have, almanacks that predicted it; but it does not follow from thence that they knew he gave light as soon as he rose. This is what I claim as my discovery. If the antients knew it, it must have been long since forgotten, for it certainly was unknown to the moderns, at least to the Parisians, which to prove, I need use but one plain simple argument. They are as well-instructed, judicious, and prudent a people as exist any where in the world, all professing like myself to be lovers of oeconomy; and from the many heavy taxes required from them by the necessities of the state, have surely an abundant reason to be oeconomical. I say it is impossible that so sensible a people, under such circumatances, should have lived so long by the smoaky unwholesome and enormously-expensive light of candles, if they had really known that they might have had as much pure light of the sun for nothing. I am, &c.

A subscriber.

Franklin's satirical letter does not propose moving clocks forward in the spring and back in the fall, and that practice was not implemented until well over a century later. Franklin's tongue-in-cheek suggestions on various means to motivate late-sleepers to rise earlier may have influenced later policy makers. Daylight Savings Time is observed throughout most of the United States, Canada, and Europe, but as far as we know, the French government never initiated a policy of ringing bells and firing cannons at sunrise to wake sleeping Parisians.

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