Measurements from the past

[Speedy Builder5Participant @speedybuilder5]

i have a fractional Mitutoyo vernier calliper measuring in 1/128" and metric. I tend to use only the metric side of it.
BobH

[larry phelan 1Participant @larryphelan1]

Surprised that no-one mentioned the Cubit. It was good enough to build the ARK,which did not sink,unlike some others I could mention !!

[Jon LawesParticipant @jonlawes51698]

Isn't it time time went decimal?

Also, how long until the calendar starts from a date of Astronomical importance rather than of religious significance?

[not done it yetParticipant @notdoneityet]

They (a large group of scientists) looked into this at the time of the adoption of the SI system. I think they determined it was not easily possible, if at all.

Earth time is not religion based. It is based on the Earth spinning once, the Earth’s satellite orbiting the Earth once and the Earth orbiting the Sun. I don’t think ‘atomic clocks’ have much to do with religion – or do you?

Remember that once in the far distant past, the Earth was at the centre of the Universe!

The calendar is just of very minor importance. The Chinese year is different from the UK, isn’t it? Which important astronomical event would you choose? The big bang? Birth of the Sun? First new moon of the millenium?

[SillyOldDufferModerator @sillyoldduffer]

Posted by vintage engineer on 01/01/2019 10:47:16:

I have seen references to 1/128"

…

Not often though. I suspect 1/128" is uncommon because it falls awkwardly between two stools. As a measure it's too fine for woodwork and too coarse for precision metalwork.

Dave

[V8EngParticipant @v8eng]

Things willl improve when right minded people get back to realising that the Earth is flat..

[BazyleParticipant @bazyle]

Greek city states started each month when someone saw a new moon (or perhaps it was full moon). Cloudy day? Still old month. So dates are weather dependent! (I'm still in November)
From a caveman's point of view only distance and time needed to be measured, and perhaps like Americans they used travel time for distance too. They could easily see the passing of a day so that is likely the first unit and decided on a division based on 60. So perhaps we should have micrometres measuring 1/3600 of something to be consistent.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by SillyOldDuffer on 01/01/2019 14:00:36:

Posted by vintage engineer on 01/01/2019 10:47:16:

I have seen references to 1/128"

…

Not often though. I suspect 1/128" is uncommon because it falls awkwardly between two stools. As a measure it's too fine for woodwork and too coarse for precision metalwork.

Dave

.

… But the binary series continues

[ we've been here before, though, so I won't labour it ]

MichaelG.

[Brian GParticipant @briang]

Posted by Jon Lawes on 01/01/2019 12:57:51:

Isn't it time time went decimal?

Also, how long until the calendar starts from a date of Astronomical importance rather than of religious significance?

Why change? The principle applied by the Meridian Conference in choosing Greenwich as the prime meridian because it was most widely used on charts could also be said to apply to CE and BCE dates. It is bad enough having to allow for OS (Julian) dates of historic events without adding a third and equally arbitary system.

Brian

[Tim StevensParticipant @timstevens64731]

For Bazyle: to the caveman, the calendar was important as soon as hunting and gathering ceased to be the sole method of survival. What was needed by then, the earliest of the Neolithic, was a way to renew the gene-pool of the family, its animals and its crops. Those who did not do this died out, sooner or later, because of in-breeding. So, how do you do this? By meeting up with other groups and exchanging DNA. So, there was a need to meet at a place others would know of, at a date others would know of – and this is a seriously complex business. It relies on recognised landmarks, and a common calendar of some sort, known to everyone who might be needing to renew their DNA too – ie most folk.

This idea can explain details which have puzzled archaeologists (and me) – but just think. What is special about the neolithic landscape? One thing stands out – It is dotted around with clearly recognisable landmarks, and most of them seem to be kitted out with astronomical clocks of some sort. With them it was possible to be at the right place at the right time, otherwise, well, how else could you do it?

See you at the Ring of Brodgar the day after the next vernal equinox, OK?

Cheers, Tim

Edited By Tim Stevens on 01/01/2019 16:15:15

Edited By Tim Stevens on 01/01/2019 16:16:06

[LambtonParticipant @lambton]

A Dictionary of Scientific Units by H G Jerrard and D B McNeill states:

“ Mil(length). A unit of length equal to 1/1000 inch. The name was given to the unit by James Cocker (Liverpool) in 1858 but did not come into general use until its appearance in The Journal of the Institute of Telegraph Engineers in 1872. A thousandth of an inch is also called a thou”

Eric

[Neil WyattModerator @neilwyatt]

Posted by Bazyle on 01/01/2019 14:19:13:

They could easily see the passing of a day so that is likely the first unit and decided on a division based on 60. So perhaps we should have micrometres measuring 1/3600 of something to be consistent.

Blame the Babylonians.

They had twelve fingers.

Neil

[Neil LickfoldParticipant @neillickfold44316]

In Western PA, North of Pittsburgh, they use the term mills for thousands of an inch. Until then I had never known it to be referenced to linear measurement, but to volume like cc. As to its origins have no clue, but what has been mentioned does seem very feasible. I think James Watt made micrometers in 0.001 inch graduations in his time. So it has been around a while.

[Mike PooleParticipant @mikepoole82104]

How about, gnats c**k, fly s**t, or for the Aussies a Mickey whisker,

Mike

Edited By Mike Poole on 02/01/2019 21:08:14

[Nick Clarke 3Participant @nickclarke3]

Posted by Mike Poole on 02/01/2019 21:06:12:

How about, gnats c**k, fly s**t, or for the Aussies a Mickey whisker,

Mike

Edited By Mike Poole on 02/01/2019 21:08:14

While the first two are familiar I have not heard of the third. Taking the others as examples what, for heavens sake is a mickey?????

Don't answer please!

[Tim StevensParticipant @timstevens64731]

The Babylonians were keen on fractional methods, as much of their maths was involved in dividing inheritances, and carving up areas of land. For them, the idea of sixty bits making a whole was very sensible, as it could be shared out equally among 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 30, and sixty.

Cheers, Tim.

PS when I was an apprentice, one of the older workers used expressions such as 'Two and a half and three of them little uns.'

[HopperParticipant @hopper]

Posted by SillyOldDuffer on 01/01/2019 14:00:36:

Posted by vintage engineer on 01/01/2019 10:47:16:

I have seen references to 1/128"

…

Not often though. I suspect 1/128" is uncommon because it falls awkwardly between two stools. As a measure it's too fine for woodwork and too coarse for precision metalwork.

Dave

Although, in the 1800s, metal lathe work was commonly measured with a steel rule and plain calipers. 1/64" was considered high precision back in James Watt's day through much of the 19C. In fact his piston to bore fit tolerance was nowhere near as close at that in his early engines. So there could have been a time as things progressed when "half a 64th" on a standard ruler morphed into the higher precision 1/128th.

The mass production of micrometers in the late 19C probably made the old 1/128th redundant.

I've seen old steel rulers in America marked in 100ths. Metric inches anyone?

[Bill PudneyParticipant @billpudney37759]

In the early 70s, I spent some time as a Work Study Engineer. We used mechanical digital stopwatches, where a full turn of the hand was one minute and the dial was calibrated in 1/100 of a minute. It was fairly easy to read the watch to 0.01 of a minute, very quickly and accurately. Of course the calculations "back in the office" were so much easier with decimal minutes. We also used slide rules as electronic calculators hadn't been invented yet, but that's another story……

cheers

Bill

[Tim Taylor 2Participant @timtaylor2]

A "mil" is indeed = 0.001".

It is still commonly used in some areas such as machinery alignment where you will see offset expressed as mils and angularity as mils/inch.

Tim

[HopperParticipant @hopper]

Posted by Bill Pudney on 03/01/2019 01:40:11:

In the early 70s, I spent some time as a Work Study Engineer. We used mechanical digital stopwatches, where a full turn of the hand was one minute and the dial was calibrated in 1/100 of a minute. It was fairly easy to read the watch to 0.01 of a minute, very quickly and accurately. Of course the calculations "back in the office" were so much easier with decimal minutes. We also used slide rules as electronic calculators hadn't been invented yet, but that's another story……

cheers

Bill

Ah, the despised "Grey Ghosts" with their stopwatches doing time and motion studies. As an apprentice I was instructed to carry a spanner or piece of metal in my hand at all times when walking about the factory, whether en route to the cafeteria or just lollygagging about as apprentices do. That way the Grey Ghosts would record your activity as "delivering tool" or "delivering part" instead of "idle". Many hundredths of minutes were doubtlessly wasted by this cunning subterfuge.

Edited By Hopper on 03/01/2019 03:58:24

[Danny M2ZParticipant @dannym2z]

Posted by Clive Hartland on 31/12/2018 22:27:00:

So we had better add the military MIL. which in a full circle gives 6400 MILS, 1 MIL subtends 1 meter at 1000 meters so it is easy to use for artillery corrections annd for spotters to give corrections for fall of shot. To add that you can get Theodoilites scaled in MILS.

Clive

Spot on Clive. I use a rifle-scope with a MIL dot reticule.The 'dots' subtend 100mm at 100 metres which makes things a bit easier when calculating wind drift and offset when target shooting with .22's.

* Danny M *

Edited By Danny M2Z on 03/01/2019 04:16:53

[Ian S CParticipant @iansc]

Hopper mentions carrying something about the workshop, reminds me of what my dad said when I joined the RNZAF, "you can get just about any where on an Airforce Station if you have a clipboard with some papers on it." It worked back in 1964 for me as it had during WW2 for dad.

1/128" was the model, and general engineers measurement until micrometres became widely available. I did read of one of the old atmospheric steam engines (in Cornwall I think), it was said that it was very accurate in the bore as you could barely fit a penny between the two.

Ian S C

[SillyOldDufferModerator @sillyoldduffer]

Posted by Hopper on 03/01/2019 03:56:27:

Posted by Bill Pudney on 03/01/2019 01:40:11:

…

Ah, the despised "Grey Ghosts" with their stopwatches doing time and motion studies. As an apprentice I was instructed to carry a spanner or piece of metal in my hand at all times when walking about the factory, whether en route to the cafeteria or just lollygagging about as apprentices do. That way the Grey Ghosts would record your activity as "delivering tool" or "delivering part" instead of "idle". Many hundredths of minutes were doubtlessly wasted by this cunning subterfuge.

…

And of course these brilliant subterfuges fooled no-one. They were the tip of an iceberg – labour didn't trust management and management didn't trust labour – both with good reason!

Over about 30 or 40 years much of traditional British industry gradually became unprofitable due to the failure to fix high-overheads and low productivity. Made it easy for foreign competitors to get the work. No wonder when the Board were deciding what to do next with their money, investing abroad and starting again became so attractive…

Dave

[Ron ColvinParticipant @roncolvin83430]

Posted by SillyOldDuffer on 03/01/2019 10:26:37:

Posted by Hopper on 03/01/2019 03:56:27:

Posted by Bill Pudney on 03/01/2019 01:40:11:

…

Ah, the despised "Grey Ghosts" with their stopwatches doing time and motion studies. As an apprentice I was instructed to carry a spanner or piece of metal in my hand at all times when walking about the factory, whether en route to the cafeteria or just lollygagging about as apprentices do. That way the Grey Ghosts would record your activity as "delivering tool" or "delivering part" instead of "idle". Many hundredths of minutes were doubtlessly wasted by this cunning subterfuge.

…

And of course these brilliant subterfuges fooled no-one. They were the tip of an iceberg – labour didn't trust management and management didn't trust labour – both with good reason!

Over about 30 or 40 years much of traditional British industry gradually became unprofitable due to the failure to fix high-overheads and low productivity. Made it easy for foreign competitors to get the work. No wonder when the Board were deciding what to do next with their money, investing abroad and starting again became so attractive…

Dave

Many of the jobs that have proliferated subsequently, ones that are not exportable, intrinsically have low productivity. So that the economic decline continues.

[Howard LewisParticipant @howardlewis46836]

My turning instructor had spent his life on Capstans and Turrets on piecework. One day,a Ratefixer came and suggested changing speeds and feeds This he did, but the time for the job remained the same. The Ratefixer went away, puzzled. He had failed to spot that each time, Alf was moving the Turret further away and disengaging fast feed earlier, so that the machines was "cutting wind" as Alf put it. He was a very good instructor!

Howard

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