How were pressures measured in the 1800's?

[noahmercy]

I've seen references to psi breech measurements from the 19th century, some up to 100,000 psi :what: (thereby effectively putting to rest the old wive's tale about BP not generating high pressures). Today, we use a pressure gun with a port leading to the chamber into which is placed either a copper or lead pellet of closely controlled dimensions and composition. The gun is fired, the pellet removed and measured, and the amount of deformation compared to a chart which converts the measurements to CUP or LUP, respectively. Was this similar to the way it was done back then?

And while we're on the topic of muzzleloading ballistics, do any of you sage types know when the ballistic pendulum came into use and where I might find some info on them? I'm actually thinking of making one if I can find some detailed information. Wouldn't that be the bee's knees, to show up at a BP shoot with one of those? (Let's face it, a modern chronograph is almost indespensible for serious load development, but it's less PC than an Omega. )

Thanks, fellers. :thumbsup:

 

[jaybeach]

I believe there were three ways for measuring pressures in the 1800's:
1. "Nope, that's not enough powder"
2. Yup, that seems about right"
3. "Ooops!"

No, really - all seriousness aside - I don't have the slightest idea. Just felt like saying somethin'. :haha:

Hope you get a more intelligent answer soon.
:thumbsup:
IM jaybe

 

[robinghewitt]

Grenner used a crusher gauge for pressure and a splendid field force gauge by J H Walsh 1879 which he says was, "based on the old fashioned balista or pendulum".

Here's a cannon chrono in 1864, the screens are at the other end of the wires :thumbsup:

 

[noahmercy]

Whoa! That makes the Oehler look...shall we say, inadequate?

So they did use a crusher gauge of some sort to measure pressures. It makes sense as it is repeatable and inexpensive. I just wonder how far back that goes. :hmm:

And thank you, Squire Robin for mentioning the ballista. That term had slipped my memory and should aid in doing some online research. Me recollection ain't what it once were, me boyo. :no:

Thanks agin, and anyone feel free to pile on and add to this post. I need all the help I can get. :thumbsup:

 

[robinghewitt]

Here is Greener's crusher gauge, looks to have 5 gauges at various points along the barrel :shocking:

 

[noahmercy]

Ooooooohhhhhh...aaaaaaahhhhhhhh.(Damn! No drooling emoticon!) The sophistication of that pressure gun both surprised and pleased me. Hearkens back to the adage of there being nothing new under the sun.

Mind if I ask what tome those prints are from, Squire? I am a bibliophile, but being of limited means, I don't have some of the more obscure technical treatise, which is where my true love lies. I'm always on the lookout for titles I might luck into at one of the local book nooks.

Thanks again! :thumbsup:

 

[robinghewitt]

The chrono is from the London Illustrated News, the crusher is from Greener's wonderful book, "The Gun and it's development".