Sunday 2 June 1661

(Whitsunday). The barber having done with me, I went to church, and there heard a good sermon of Mr. Mills, fit for the day. Then home to dinner, and then to church again, and going home I found Greatorex (whom I expected today at dinner) come to see me, and so he and I in my chamber drinking of wine and eating of anchovies an hour or two, discoursing of many things in mathematics, and among others he showed me how it comes to pass the strength that levers have, and he showed me that what is got as to matter of strength is lost by them as to matter of time. It rained very hard, as it hath done of late so much that we begin to doubt a famine, and so he was forced to stay longer than I desired. At night after prayers to bed.

36 Annotations

daniel   Link to this

"...and so he was forced to stay longer than I desired."

yes, sam, we all surely know the feeling. even the best of guests must depart eventually.

A. De Araujo   Link to this

"at night after prayers to bed" if my memory is correct it is the first time he mentions praying before going to bed.

Sjoerd   Link to this

"what is got as to matter of strength is lost by them as to matter of time"

If you read "strength" to be what we call "force" these days it should be "...as to matter of DISTANCE".

But Newton isn't going to watch his apple fall until next year, isn't he ?

chris   Link to this

Sorry to persist with the wig thing; but does "the barber having done with me" indicate running repairs on the flowing locks, or a shave and clippers, or perhaps all of the above?
p.s. Isn't the use of "doubt" interesting?

dirk   Link to this

bedside prayers - re A. De Araujo

Last mentioned on Sunday 19 May 1661:
"I took leave and went home, where to prayers (which I have not had in my house a good while), and so to bed."

daniel   Link to this

"the barber"

this could also have been letting blood as barbers also did this-though Sam usually mentions this ritual.

Ruben   Link to this

"what is got as to matter of strength is lost by them as to matter of time"

"strength" is certainly what we call "force" these days but “time” I think, represents “velocity” and not distance.
Velocity is “distance x time”. As both ends of the lever move at the same lapse of time but to different distances, velocity is the real modern translation.
I suspect that Greatorex was demonstrating one of Galileo’s experiments. Nothing herd yet from Newton…

Jesse   Link to this

"what is got as to matter of strength is lost by them as to matter of time"

This is curious to me. I read it as the stronger the lever the lever becomes the less it lasts. Perhaps as the length of the lever increases (i.e. the gain in strength) there’s greater stress on it and it’ll break sooner?

Australian Susan   Link to this

Sam gets himself smartened up for Church on Whitsunday, which was also a traditional time for women to have new clothes, but no mention of Elizabeth being caught out in any extravagance nor of Sam being proud of her appearance. In fact, no mention at all......Where is she??

Sjoerd   Link to this

A lever , like a crowbar for instance , can lift a very heavy crate for maybe an inch.
To do this you would have to move the handle down for maybe 10 inches, increasing the force by ten (not considering things like friction and the weight of the crowbar itself).
So while you DEcrease the force needed on the handle side, you INcrease the distance it has to move.
And as Ruben points out, the speed as well.
You could demonstrate this using a hinged rod and some weights, maybe that is what Greatorex did.

Great name for a scientist/alchemist, isn't it ?

Mary   Link to this

Bedside prayers?

It's Sunday. Much more likely to be household prayers for all members of the extended family living at the Pepys' Seething Lane lodgings. This is a practice that persisted into the 20th Century in many larger households in this country. Even little Daisy Ashford ("The Young Visiters") describes it.

Mary   Link to this

No wig for Sam.

Sam will not start wearing a periwig until 1663. He would probably have mentioned any blood-letting (he's always careful of health matters). Most likely that this call was for a trim and a shave, getting spruced up for Whitsunday attendance at church. Not very likely that he had a 'shampoo'; he would surely have mentioned any application of water to the head, as he was wary of getting his extremities (and other parts of him) wet and, at a later date, will complain that washing the feet is a very risky business.

Not that shampoo as such had been invented, but scented waters (flower or herb based) had been available for many years for freshening up greasy and dirty locks. Gilly flower water was one mentioned fairly often.

Pedro.   Link to this

"what is got as to matter of strength is lost by them as to matter of time"

I think Ruben and Sjored are on the right track. From one of the many sites on levers;
Lever Types
Bones of the body act as levers (a mechanical device) which creates mechanical advantage of strength or speed by producing a turning motion about an axis.

There is probably a trade off between strength and speed (distance x time), Greatorex would not require Newton’s acceleration?

Ruben   Link to this

"what is got as to matter of strength is lost by them as to matter of time"

they are 3 types of levers. It was Aristotle who demonstrated and classified them. He said that if he had a long enough lever and a fixed site he could move the earth.
Another genious, Galileo, demonstrated that force and movement are related. He discovered the rules that govern the pendulum, giving way to Grandfathers clocks,the metronome, the rules of inertia and giroscopes.
Greatorex knew Galileo’s work and probably demonstrated as Sjoerd suggested.
No need for Newton or Einstein!
Remember that SP had no formal education in what was called then Mathematics (I posted something on this subject: see “education”)

Kevin Sheerstone   Link to this

Levers and such.

Based on this entry, and several previous examples, I am beginning to think that Sam is simply not 'mechanically inclined'. It is true of course that he cannot have been familiar with Newtonian principles, or calculus, but the basic principles of leverage require neither. I have always imagined, on no good authority, that his education at St Paul's, although undoubtedly heavily weighted in favour of the classics, would have included at least a smattering of 'Euclid', and perhaps Archimedes.

Formal education aside, Sam, although no seaman, has certainly been on more than a few ships and would surely have seen the block and tackle in use. That is, after all, simply a series of levers in rotation: I would have thought it common knowledge that with a purchase of (say) 10:1, ten length- units of rope have to be pulled for every unit of lift.

Kevin Sheerstone   Link to this

Ruben above - sorry, I should have checked.(Your entry wasn't there when I started typing!)

deepfatfriar   Link to this

Archimedes: "Give me where to stand, and I will move the earth."

Quoting Aristotle?

Ruben   Link to this

deepfatfriar:
you are right. Just a lapsus between the name of the classics...or may be a half a century old memory bit, stored in the wrong place!

A. Hamilton   Link to this

Household prayers

My great-great grandfather, staunch Presbyterian, used to hold family prayers on a regular basis, to the dismay of his grandchildren. A nephew brought back an African Gray parrot from a trip to the Congo, and gave it to the household, where the grandchildren dicovered how clever it was. One day the family head called everyone together for prayers and started up. From the back of the room came the parrot's voice:"Aw, dry up!"

Rich Merne   Link to this

Kevin Sheerstone at al.
Yes Kevin and even more demonstrably the common capstan on ships of those times. The modern equivalent of the capstan being the simple winch, which may be seen on every modern boat from about 17 feet up; (sailboats generally that is)
"Lost in time". I think S., surprisingly may be a little lost in time here. 'Time', has actually nothing to do with the fundamental principal of levers which S. is talking about. This principal, of Archimedean fame, concerns itself with 'mechanical advantage' to use the old fashioned term. In a simple lever set-up, the ratio of the opposing unequal lengths of lever arm about it's fulcrum, is identical to the ratio of the applied force and the resultant force of reaction, (discounting minor aberrations which may not intrude on the purity of the principal). ie. in a simple lever of 3 M /fulcrum /1 M, a force of 1KN applied through a distance of say 0.3M will move 1000Kg. or 1 Tonne through 0.1M, ie. a three to one lever doing three to one work. This will all happen in the same time span. Bringing 'time' into it, obscures the principal in discussion. Hope I'm accurate here as I'm running****........

Ann   Link to this

"It rained very hard, as it hath done of late so much that we begin to doubt a famine, "
Chris notes the interesting use of "doubt" above. OED says doubt can mean "With infinitive phrase or objective clause: To fear, be afraid (that something uncertain will take or has taken place)" Also: "b. To suspect, have suspicions about. c. With infin. phrase or clause: To apprehend; to suspect." Also, to fear.

So, Sam fears that with so much rain, there WILL be famine, not that there won't be one.

I love looking up words whose meaning we take for granted and learning an entirely new twist on them!

Mary   Link to this

"we begin to doubt a famine"

According to an L&M footnote, there was indeed a sharp rise in the price of grain from 1660 to 1661, so Sam's doubts may have been justified.

Ruben   Link to this

"what is got as to matter of strength is lost by them as to matter of time"
Rich, you wrote: “Bringing "time" into it, obscures the principal in discussion.”
It is SP that says that. We are trying to understand why SP brings time into it!
I do not thing he did not understand. On the contrary, I think Greatorex explained to him the new insights about the relation between levers and movement and that of course includes time…and velocity.

Sjoerd   Link to this

Pepys Greatorex Huygens

Pepys has his "ear to the ground" here and reports what he remembers.
"Time" is not a very interesting factor in regular levers, it is much more interesting in the context of pendulums.
On january 23st Samuel, together with Greatorex, paid his first visit to Gresham College base of the Royal Society.

The dutchman Christiaan Huygens lives in London around this time, is made a member of the Society, and must have discussed levers, pendulums and air pumps with Greatorex. Huygens was the first to put forward the concept of Impetus (Force x Time) and will build the first reliable pendulum clock. We know Greatorex and Huygens actually built Air pumps in 1661.

Reliable clocks would prove enormously interesting for the navy, because they were the only way to measure longitude. This was one of the main goals of the Royal Soc. Still it would take another century for a solution to the problem to be accepted by the Society.

Huygens is one of those people you would like to have heard from in the diary, but don't.

http://www-gap.dcs.st-and.ac.uk/~history/HistTo...

Pedro.   Link to this

Pepys, Jonas Moore.

A few days ago Sam was talking with Jonas Moore who had given support to Flamsteed and his work on clocks/latitude see;

http://www-gap.dcs.st-and.ac.uk/~history/Mathem...

john lauer   Link to this

For the record: v = d / t (not d x t); d = v x t

Not surprising that Sam could not perfectly relate the concepts of distance and time, which Greatorex did not have the language and terminology to express clearly to him, before Newton!

Ruben   Link to this

Sjoerd & Pedro & John:
Now you are speaking!

vicente   Link to this

Leverage was used. I'm sure that they used poles to lever up crunched coaches after the wheel fell off. They just could not express wot it is they don did. {v=d/t or f=ma or any other funny way of saying I did it} But ask how many fish make a bakers dozen and answer they would.They also knew how many fart[h]ings there were in 5s 1d 3/4., before any get out their free calculator[or aba cus].

dirk   Link to this

"levers ... what is got as to matter of strength is lost by them as to matter of time"

Let's try the simplest "translation":

[Using a lever,] if you gain strength (if it becomes easier) you have to exercise your (now smaller) force for a longer time (by moving the lever over a longer distance than you would have had to move the original object)to do the job.

Force x time = work done

Am I wrong?

Rich Merne   Link to this

Ruben,
Sorry, I insist, the relations between levers arms and their strenghts does not ('include') embrace the element of either time or velocity.
John Lauer's little header is of course correct, but it has nothing to do with the principal of 'the strenght that levers have'.

Sjoerd   Link to this

Today we reserve very strict meanings for some of these words which were not so established then.

Work = force x distance
(for a lever: time does not come into it , Rich is right)

Impulse = force x time

and

Momentum = mass x velocity

The last two were used by Huygens studying bouncing balls and pendulums.
For instance, the change in momentum in a billiard ball is equal to the total impulse it gets from the cue.

A concept called "Vis Viva" (living force) was used as well, which Huygens expressed as mass x velocity^2.
This looks very much like the formula for Kinetic Energy 1/2.m.v^2, but the concept of energy was developed later.

Ruben   Link to this

E pur si muove!

E   Link to this

If you move the handle end of your lever at a constant speed, then yes it will take longer to shift something the same distance with a "stronger" (longer) lever.

This is much more obvious in the related matter of a block and tackle (pulley) setup as used on ships, where you have to pull through much more rope on a "stronger" system. We now encapsulate the relationship in the equation work = force x distance, but it was not an unreasonable guess to think it was the length of time the lesser force operated that produced the magic effect, rather than the distance of movement.

Rich Merne   Link to this

Greatorex, 'great name for scientist' etc.
Sjoerd, for interesting geneology of the name 'Greatorex' and some digressive but amusing commentary, try link below if you havn't already done so.
http://www.winster.org/History/Greatorex/The%20...

Jackie   Link to this

It is fascinating to see what we regard now as basic science and common knowledge being at the cutting edge of scientific debate in Pepy's time. The importance of Newton and which equations on work done being force X distance and the calculations of impulses and steady forces was a revolution - but he wasn't the only person trying to puzzle this all out.

The people thrashing these issues out were real scientific greats.

language hat   Link to this

"geneology of the name 'Greatorex'”
Rich, thanks for that interesting site! I have a problem with the etymology, though:
“The ‘Great’ is from the Teutonic languages… and ‘raches’ or ‘rakes’ is a similar word in mining terminology. It means a vertical vein of ore, usually lead…”
This word “rakes” is only attested from the 17th century, and I think it’s stretching plausibility to project it back half a millennium or more. There are a number of earlier senses of “rake” (like ‘way, path; esp. a rough path over a hill, a narrow path up a cleft or ravine’) that are more likely to be relevant here.

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