Rulers of the Ancient World: period correct measuring tools • Hacker News Board

Re: Rulers of the Ancient World: period correct measuring tools

#31

Post by kragen » Thu, Jul 11, 2024, 6:52 PM UTC

jzxy wrote: post #23

legitster wrote: post #13

These are beautiful - but the project kind of misrepresents how ancient measurements worked. Outside of building sites in Medieval Europe it would be common for the head architect to have the outline of his hand on a sign. The idea being that even "crude" measurements like hand-widths and thumb lengths would be universally agreed upon for the project. You can see some of this at work watching documentaries of the Gué…

>It wasn't until empires and mass manufacturing that the need for "standardized" measurements. You have the cause and effect backwards. Mass manufacturing didn't create a need for standardized measurements. Standardized measurements allowed the existence of mass manufacturing. Mass manufacturing wasn't even close to a possibility before that. Measurements weren't created for a need that didn't even exist yet. You can…

https://en.wikipedia.org/wiki/History_of_geodesy says

aristotle: off by a factor of almost 2

eratosthenes: off by -2.4–+0.8%, or maybe up to 15%, because we aren't sure how big his stadia were

ptolemy: at first accepting eratosthenes' figure, he later switched to a figure that was about 30% low

aryabhata: probably off by about 0.8%, though again it's unclear how big his yojana were

caliph al-ma'amun: probably off by about 0.45%, and in this case the source of error is not the unit of measurement but the different accounts of how many of them they measured in a degree

the fact that 1500 years ago aryabhata bothered to give the earth's diameter as 1581 1⁄24 yojanas strongly suggests that he believed the size of a yojana to be defined to within less than 26 parts per million; remember that he had to do all his calculations mentally or by hand, so extra significant figures were extra significant labor

however, all of these measurements postdate the monuments of rameses from 3200 years ago, which contain multiple precisely measured statues constructed all over egypt (though i don't have references on what the tolerances were on the statues)

Re: Rulers of the Ancient World: period correct measuring tools

#32

Post by legitster » Thu, Jul 11, 2024, 6:52 PM UTC

btbuildem wrote: post #27

legitster wrote: post #13

These are beautiful - but the project kind of misrepresents how ancient measurements worked. Outside of building sites in Medieval Europe it would be common for the head architect to have the outline of his hand on a sign. The idea being that even "crude" measurements like hand-widths and thumb lengths would be universally agreed upon for the project. You can see some of this at work watching documentaries of the Gué…

That's a great observation! Measuring with ruler / tape / string isn't the most reliable way to do it -- using a full length of something like a stick, is. This is the basis of the simplest of jigs: cut a piece, then cut all the other pieces you want to be like that piece, by using that piece as a guide. The need for specific measurements seems to have arisen alongside industrialization of building processes - in the…

Another fascinating tidbit I learned from the curator at an air museum - the transition from wooden airplanes to metal airplanes was not a material constraint! In many ways, wood continued to be a superior building material for airplanes even by the advent of WWII.

The transition from wood to metal was driven primarily as a manufacturing improvement. Wood changed and warped as you built the airplane, and it required a lot of expertise and knowledge of the properties of wood to properly tie together the structure.

Metal weighted more and cost more - but you could step away from a production line and the piece would not have changed shape on you.

Re: Rulers of the Ancient World: period correct measuring tools

#33

Post by jacobolus » Thu, Jul 11, 2024, 6:56 PM UTC

fusslo wrote: post #8

thats a really cool project. I would've loved making them while taking my history electives in college. There's something really nice about making something that gets tied to what you're learning. Since they talk about Roubo, can I ask if any other amateur woodworkers just don't use a ruler? I used to 3d model everything and make simple dimension drawings for parts. Since I started mostly using hand tools I just stop…

You might enjoy https://www.byhandandeye.com/books/ which is all about this style of design.

Re: Rulers of the Ancient World: period correct measuring tools

#34

Post by throw0101c » Thu, Jul 11, 2024, 6:59 PM UTC

legitster wrote: post #32

btbuildem wrote: post #27

Earlier quoted context omitted.

That's a great observation! Measuring with ruler / tape / string isn't the most reliable way to do it -- using a full length of something like a stick, is. This is the basis of the simplest of jigs: cut a piece, then cut all the other pieces you want to be like that piece, by using that piece as a guide. The need for specific measurements seems to have arisen alongside industrialization of building processes - in the…

Another fascinating tidbit I learned from the curator at an air museum - the transition from wooden airplanes to metal airplanes was not a material constraint! In many ways, wood continued to be a superior building material for airplanes even by the advent of WWII. The transition from wood to metal was driven primarily as a manufacturing improvement. Wood changed and warped as you built the airplane, and it required…

> In many ways, wood continued to be a superior building material for airplanes even by the advent of WWII.

A mostly-wood WW2 airplane:

* https://en.wikipedia.org/wiki/De_Havilland_Mosquito

Re: Rulers of the Ancient World: period correct measuring tools

#35

Post by [deleted] » Thu, Jul 11, 2024, 7:01 PM UTC

davidgay wrote: post #26

mitthrowaway2 wrote: post #12

Earlier quoted context omitted.

I don't think objections to US customary units are because of base-12 vs base-10. I think it's because it's 12 inches to 1 foot, 3 feet to 1 yard, 1760 yards to 1 mile, 3 tsp to 1 tbsp, 2 tbbsp to 1 fl. oz, 40 fl. oz per quart, 2 quarts per pint, 4 quarts per gallon, 31.5 gallons per barrel (or 42 if oil), 16 ounces per pound, 2000 pounds per ton (or 2240 if long ton), 1000 mil per inch, and so on. It's not just a ba…

> 40 fl. oz per quart, That's the imperial quart. The US quart is 32 fl. oz. And, of course, the US fl. oz is slightly different from the imperial one. And neither is 1 (weight) oz of water (but at least the weight ozes are the same in US and imperial...).

[deleted]

Re: Rulers of the Ancient World: period correct measuring tools

#36

Post by wongarsu » Thu, Jul 11, 2024, 7:29 PM UTC

BitwiseFool wrote: post #4

While I am no apologist for the measurement system we use here in the United States, I realized something interesting when trying to explain why almost all of our units consist of easily divisible sub-units. Imagine you needed to split something up into halves, thirds, fourths, sixths, etc.. If you imagine doing this with paper, it's fairly easy. Now imagine Metric, and the need to split something into 10 even pieces…

> Now imagine Metric, and the need to split something into 10 even pieces

That's only true if you assume that in metric everything starts out as 1, 10 or 100 units. But that's not really what happens.

For example kitchen appliances and furniture basically works on multiples of 60cm: an oven or dishwasher fits in a 60cm slot, and accordingly your cabinets will be one appliance wide (60cm), two appliances wide (120cm) or half an appliance wide (30cm). And you will find that halfes, thirds, fourths or sixths of 60cm are easy to calculate. Lots of other furniture works on multiples of 80cm. Those don't have nice thirds, but halves, fourths, eights, sixteenths, doubles, triples, quadruples all work great.

And this happens not only in furniture but in everything. Having things 1.2, 1.5 or 1.6 of whatever unit you are measuring is common and allows you to have nice fractions. We just never write them as fractions. And honestly 45 + 7.5 is so much easier to do that 3/8th + 1/16th (of 120)

Re: Rulers of the Ancient World: period correct measuring tools

#37

Post by fhars » Thu, Jul 11, 2024, 7:44 PM UTC

jzxy wrote: post #23

legitster wrote: post #13

These are beautiful - but the project kind of misrepresents how ancient measurements worked. Outside of building sites in Medieval Europe it would be common for the head architect to have the outline of his hand on a sign. The idea being that even "crude" measurements like hand-widths and thumb lengths would be universally agreed upon for the project. You can see some of this at work watching documentaries of the Gué…

>It wasn't until empires and mass manufacturing that the need for "standardized" measurements. You have the cause and effect backwards. Mass manufacturing didn't create a need for standardized measurements. Standardized measurements allowed the existence of mass manufacturing. Mass manufacturing wasn't even close to a possibility before that. Measurements weren't created for a need that didn't even exist yet. You can…

That is also why now country became industrialized before they gave up their ancient foot/inch/ounce measurement systems and became fully metric.

Or something like this.

Re: Rulers of the Ancient World: period correct measuring tools

#38

Post by saalweachter » Thu, Jul 11, 2024, 8:07 PM UTC

btbuildem wrote: post #27

legitster wrote: post #13

These are beautiful - but the project kind of misrepresents how ancient measurements worked. Outside of building sites in Medieval Europe it would be common for the head architect to have the outline of his hand on a sign. The idea being that even "crude" measurements like hand-widths and thumb lengths would be universally agreed upon for the project. You can see some of this at work watching documentaries of the Gué…

That's a great observation! Measuring with ruler / tape / string isn't the most reliable way to do it -- using a full length of something like a stick, is. This is the basis of the simplest of jigs: cut a piece, then cut all the other pieces you want to be like that piece, by using that piece as a guide. The need for specific measurements seems to have arisen alongside industrialization of building processes - in the…

Growing up, I always heard "measure twice, cut once", but in almost every context I've actually had to measure and cut, "measure once, cut twice" [or more] is actually the way to go. Cut with a jig or a stop, stack your layers of fabric together and cut them at the same time -- any time you can avoid measuring the same length twice, the better your two pieces will match up.

Re: Rulers of the Ancient World: period correct measuring tools

#39

Post by myself248 » Thu, Jul 11, 2024, 8:13 PM UTC

fusslo wrote: post #8

thats a really cool project. I would've loved making them while taking my history electives in college. There's something really nice about making something that gets tied to what you're learning. Since they talk about Roubo, can I ask if any other amateur woodworkers just don't use a ruler? I used to 3d model everything and make simple dimension drawings for parts. Since I started mostly using hand tools I just stop…

You're not the only one. https://www.leevalley.com/en-us/shop/tools/hand-tools/markin...

Re: Rulers of the Ancient World: period correct measuring tools

#40

Post by saalweachter » Thu, Jul 11, 2024, 8:14 PM UTC

davidgay wrote: post #26

mitthrowaway2 wrote: post #12

Earlier quoted context omitted.

I don't think objections to US customary units are because of base-12 vs base-10. I think it's because it's 12 inches to 1 foot, 3 feet to 1 yard, 1760 yards to 1 mile, 3 tsp to 1 tbsp, 2 tbbsp to 1 fl. oz, 40 fl. oz per quart, 2 quarts per pint, 4 quarts per gallon, 31.5 gallons per barrel (or 42 if oil), 16 ounces per pound, 2000 pounds per ton (or 2240 if long ton), 1000 mil per inch, and so on. It's not just a ba…

> 40 fl. oz per quart, That's the imperial quart. The US quart is 32 fl. oz. And, of course, the US fl. oz is slightly different from the imperial one. And neither is 1 (weight) oz of water (but at least the weight ozes are the same in US and imperial...).

The imperial fl. oz is 1 weight oz, at least within the margin of error of 1824.

It's a shame that everyone broke the "a pint is a pound, the whole world 'round" relationship. The US standardized its pint too big, the UK switched from a 16 to 20 oz pint.