I posted the partial results of a study I made to determine whether a 2.75-inch Whitworth bolt is of British or Confederate origin based on its weight, the volume of the projectile as determined by liquid displacement and its comparison to the weight of British cast iron versus Confederate. I conducted this study because at one of the Richmond shows six of the most knowledgeable “experts” that I know were debating whether a 2.75-inch Whitworth bolt was of British or Confederate manufacture. The bolt had been cleaned up so measurements across the flats and angles were inconclusive. It had an alignment “dimple” on the nose, a rough base, was 9.4-inches in length and weighed 12.24 pounds. Based on my study, I made certain conclusions that Dave the Plumber ask me to share on this forum.
My good friend and distinguished colleague Peter George has taken exception to my findings. When I made this post I went out of my way to avoid a conflict of opinions and asked anyone that wanted to discuss my findings to contact me. I did this because I had genuinely hoped that I could avoid going on this forum and going head-to-head with the World’s experts on Civil War ordnance over a simple liquid displacement test finding. It appears that I have failed.
Pete is indeed one of the World’s experts along with Jack Melton, Jack Bell and a few other exceptionally knowledgeable individuals. I wish that I had their “hands-on” knowledge. In fact, Pete contacted me within a few hours of my post to express this friendly concern. I appreciate this as our friendship goes back thirty years to when he had his relic shop in Fredericksburg. In fact, he has made a tremendous contribution to my encyclopedia and I couldn’t be so close to publication if he had not shared his data base with me.
When he called we had a congenial conversation and I noted his exceptions and attempted to explain my findings. Unfortunately, it appears that I have failed.
While I appreciate his comments, I must reply to defend my displacement study as I’m quiet certain that it will survive after being put under a microscope and the “spot-light” of justice.
Pete said that the “vast majority” of Whitworth bolts sold by Bannerman’s are British made, not Confederate.” I cannot dispute this other than to note that most collectors believe pristine specimens came from Bannerman’s as I stated. Based on displacement testing, I concluded that those that have or don’t have “dimples” on the nose that weigh less than 12.5 pounds are Confederate because I haven’t found a CSA specimen that is about 9.4-inches in length that weighs more than that. They can’t because of the lighter specific gravity of CSA iron. You can’t get ten pounds of beans in a five pound bag. The volume of the Confederate bolt is a limitation. The British bolt of this size (9.4-inches) is significantly heavier, about 13.3 pounds when new. Page 329 of Pete’s revised 1993 edition shows a short British bolt (8.87-inches in length) that weighs 12.625 pounds, supporting my findings that British bolts weigh more than 12.5 pounds... even the short pattern. If the additional one-half inch was added to bring it to 9.4-inches, Pete’s specimen would weigh what General Abbot recorded in his book. Holley (page 34) states the 2.75-inch shell that is only 7-inches in length weighs 12.156 pounds (including fuse and bursting charge) illustrating just how heavy British cast iron is compared to other services. Unfortunately, I think the length is a typo and should read 9.0-inches.
In addition, I didn’t say Bannerman’s didn’t sell British bolts, because they did. But based on empirical data and the collections I have visited it appears most of the 2.75-inch bolts in pristine condition that I have seen weigh less than 12.5 pounds so you can draw your own conclusions as to whether these were sold by Bannerman’s and/or the ratio of their 2.75-inch bolt sales.
I didn’t say all 2.75 bolts are identical and I meant to be clear that the specimens that I conducted liquid displacement tests on were relatively identical in length and volume. I acknowledged the windages were different with CSA Whitworth’s having more windage for reasons of safety.
Pete states that “…Bannerman’s initial purchases (1870s) were mostly the captured cargo of Confederate blockade-runners.” While I cannot dispute this logic (they somehow ended up at Bannerman’s), my research has been unable to document whether they came off blockade runners, from surplus federal stocks, from captured Confederate stocks, from Whitworth’s worldwide sales as the system became obsolete or a mix of all sources. I would appreciate it Pete, if you could provide the references supporting your conclusion that Bannerman’s stocks were mainly from captured blockade runner cargos and not also from captured Confederate stocks or from federal or foreign sales surplus. I would like to include those references in my encyclopedia.
Pete also states “toward the later 1800s, the British government sold off its obsolete stocks of Whitworth cannon projectiles, and Bannerman’s purchased many of them.”
“A Treatise on Ordnance and Armor, by Alexander L. Holley, D.Van Nostrad, London, 1865, reveals the British government adopted the Armstrong system as standard, tested the Blakely and Whitworth systems, but never adopted either of them. Whitworth was strictly an export rifle, sold world-wide to multiple nations. This is documented on pages 46-47 and pages 863–870. Page 36 specifically says, “…neither the gun nor the rifling of Mr. Whitworth’s have been yet adopted by the British government…” Numerous other sources state the British Government rejected Whitworth’s design as well (check Joseph Whitworth in “Wikipedia,” The Gun, W. L. Ruffell, and other sites). Since the British government rejected Whitworth’s design in the early 1860s, I would be curious how Pete concluded the British government sold off stocks of a projectile they never purchased for a system they never adopted “toward the later 1800s.” I would again appreciate it Pete, if you could provide the references from your research to support your statements as I would also like to include them in my work, as previously undocumented Whitworth sales to the British government.
Pete agrees with me that British cast-iron was heavier than US or CSA cast-iron, but he states “…it is not relevant in this case.” In my view, IT IS THE MOST RELEVANT FACTOR IN MY STUDY! How can you make an absolute conclusion of provenance unless you identify the origin of the cast iron (or steel), given they are so different?
There are many 2.75-inch bolt variants due to replication of the pattern, manufacturing techniques, quality control, and production line changes. It’s difficult to sort them out without using the known weights of British and Confederate cast iron. The weight of British cast iron is unique, fully documented and is not the specific gravity of the metals that Pete mentions.
Pete states British made Whitworth projectiles were made of mild steel. I won’t dispute this, but my tests confirmed the specimens I examined were made of British cast iron at 0.2685743 pounds per cubic inch. Mild steel is even heavier than British cast iron and weighs up to 0.284 pounds per square inch.
I think Pete’s statement makes my case stronger. Both British cast iron and mild steel weigh more than Confederate cast iron. A British bolt made of mild steel, the size I studied (49.52 cubic inches) would weigh up to 14.06-pounds, making it even easier to identify by weight. How can we say weight isn’t relevant? These projectiles have volume limitations due to their size and weight becomes the critical factor in making difficult identifications.
Again, one must examine the weight of the projectile and divide it by its volume in cubic inches to determine the origin of the metal. It just happens that the patterns of Confederate 2.75-inch bolts that I’ve measure do not weigh over 12.5 pounds because of their size. Furthermore, I’ve not seen one with an “alignment dimple” that weighed over 12.5 pounds. If someone has one, please let us know. This would be significant information.
Pete’s post goes into the various lengths, diameters, and diameter of the flats of British and Confederate Whitworths. I have these measurements in my Encyclopedia for the various variants, with the proper references. I most note that Pete states “…later British model’s flat base diameter is wider, being greater than 2.0-inches, whereas CS-made specimens base-diameter is 2.0” or less.” Some of the Confederate specimens I’ve seen, including the one I found at Petersburg have a base diameter of about 2.15-inches, indicating some exceptions exist.
Conducting accurate measurements are a good indication of the pattern and origin and are sufficient for the collector that doesn’t want to conduct displacement testing. I don’t dispute the value of measuring bolts and weighing specimens. I do it and it’s very informative. Holly states the British specification (page 34) for the 2.75-inch bolt is 2.73635-inches across the flats and 2.97735-inches across the angles.
Unfortunately, this is not absolutely conclusive because many specimens have been over-cleaned and are smaller than their original measurements across the flats and angles. It’s easy to remove 0.02365 inches during cleaning, or increase the projectile’s diameter by applying a protective coating.
At no point in Pete’s post did the word “displacement” appear so I must assume he places no value on displacement testing. My conclusions are based on the weight of the cast iron per cubic inch and this can only be determined by liquid displacement. I developed very accurate mathematical formulas to computer model projectile weights, but they aren’t totally accurate on small projectiles because of slight variances in projectiles. The only way you can accurately determine the volume of a projectile is to carefully determine its volume by liquid displacement.
Let me explain how to do this. Take a container just larger than the projectile and place the projectile inside. Add water using a scientific beaker and measure the exact amount of water (in milliliters) it takes to flood the container to the top of the bolt. Carefully record this value and put a mark on the container so you can refill it to that mark.
Remove the bolt, empty the container, dry it to remove all water and refill it with water to the precise mark. This value is greater so we deduct the first value (projectile in water) to determine the volume of the projectile in milliliters of water. This liquid value is converted to cubic inches to reveal the volume of the projectile.
The projectile is then weighed on a scientific scale or postal scale and its weight divided by the bolt’s volume, in cubic inches, to reveal the metal’s weight per cubic inch to five digits.
Now I repeat. If that value is approximately 0.253351 lb per cu inch or less, it’s likely Confederate cast iron. If that value is about 0.2685743 lb per cu inch, it’s British cast iron. If the weight is over 0.2685743 lb to 0.284 lb per square inch, it’s a form of pure cast iron or steel, but both are British. If the measurements and weighs are correct and the mathematics is done correctly, it produces an indisputable weight per cubic inch of iron! This isn’t “rocket science.” It’s pure physics and it’s difficult to argue with the numbers these tests produce.
I haven’t found any 2.75-inch bolts made of steel, but I don’t doubt they exist. But if they do, they will be even heavier than the 12.5 pounds that I have used as the general rule for determining whether the origin of the bolt is British or Confederate.
So based on the density of Confederate cast iron and the volume of a 9.4-inch, a Confederate 2.75-inch bolt cannot weigh more than 12.5 pounds and a British bolt of the same caliber and pattern has to weigh significantly more. General Abbot’s was 13.3 pounds. Based on this information, I rest my case.
So I agree with Pete’s request for measurements to study this further. However, I ask members to conduct liquid displacement tests on their 2.75-inch Whitworth bolts, if possible, to determine the projectile’s volume. This would be a more positive proof of origin.
If that’s impractical, I ask anyone with an accurate scale to find a 9.4-inch, 2.75-inch Whitworth bolt that has an “alignment dimple” on the nose that weighs more than 12.5-pounds. I don’t know whether the British used an alignment “dimple” and this test will tell us if they did.
If one can’t be found, it might indicate this was unique to Confederate production methods at one of the facilities that made them. Worse yet, it could indicate Bannerman’s purchased 2.75-inch bolts abroad from the countries that phased the Whitworth system out as obsolete. There is no reason to discount the idea that countries that purchased the Whitworth system didn’t produce their own ammunition! Based on the specific gravity of the cast iron they used it could produce results completely inconsistent with the weights of British and CSA bolts. Whitworth specimens that have no Civil War provenance continue to be imported to the US because of their high value and regularly show up on the collector’s market.
I only ask that you make certain that your scale is accurate because we are at the stage where we are “dynamiting mouse turds” and accurate weights are required to evaluate British versus Confederate 2.75-inch Whitworths.
Respectfully, John B.
