The Three Magic Bullets

[John Dolva]

John & Tom :

A Question please...

I have been following this thread, and it appears to me that you are basing the Tague curb shot, trajectories with the Z 313 head shot, re the Zapruder film....from the TSBD..

But at the same time, Tom has posted previous information that the head shot occurred 30 feet further

down Elm Street, than what we see within that film....and John you agreed with his information, I believe.

If so. this study would therefore not be of any use, as the findings based on Z 313 would all be in error.

E.J.Hoover's report, was that this shot had not come from the TSBD, but from the Dal Tex or another

building....

Thanks B..

1. The first shot to the head of JFK was at Z313. (Second shot fired) Stationing 4+65.

2. The second shot to the head of JFK was some 30+feet farther down Elm St. in front of Mr. Altgens. (Last/third shot fired) Stationing 4+96.

3. The Z313 shot is the one that fragmented the bullet.

Bernice, thank you for your comments.

What I'm trying to do is to show what would happen to a fragment assuming it's from z313 wihout favouring the outcome. I think it shows that a fragment from z313 is unlikely if not impossible to strike the curb and if it did, is unlikely to cause the surface of the curb to break and send fragments to Tagues cheek.

I don't agree with Toms conclusions about the last shot, AND I don't disagree with them either, I'm following his explanations to the best of my ability.

Whatever, the method is really the important thing, and can be applied to any situation. Also I haven't had (I hope someone will) any confirmation (or denial) of the methodology. I already found one mistake (however that mistake when corrected made the curb strike even more unlikely). I have very little doubt that the mark on the curb is a curtate cycloid* wheel weight balance strike and it looks like the "blond Agent'# palmed a wheel weight and not a bullet. I know that wasn't in the same place, but the likelyhood, given the trochoids* on the small section of curb cut out and Tom's accounts from his youth et.c. makes no lead pieces collected and identified as wheel weights unlikely ie. >>>they were found, and for some reason not logged as what they were. I theorise that this is to confuse things and make the Tague strike credible because if it didn't strike the curb bur rather took the more credible downward trajectory to him, the fragment would have gone skipping across any number of vehicles behind him and there is no report of anything like that. IOW they needed it to rise up as a ricochet and the curb damage fitted the bill. Now subtract the Tague strike and the field is ripped wide open. No more 'but what about Tague?'. So it's important to get this right.

*

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I understand Tague, after Walthers pointed out blood on the cheek (a matter of droplets), Tague remembers a sting on the right cheek. Left is an assumption. Apparently it was on the right cheek and the photo of the day showing a scratch on the left cheek is, according to Tague, a week old scratch. There (AFAIK) no photo of his right cheek showing any wound.

The FBI presents the curb 'cut out' upside down,

Dillard photographs it very obliquely in a way it's hard to make things out with the face of the curb dark.

This photo* presents the curb the right way up showing the trochoids, however the photo marked 'A' is actually upside down. This makes it appear that the mark is from something striking down from the left. (TSBD)

*(image)

However, there is one other photo that gets it right, so we know the photo 'A' just needs to be rotated about 150 degrees and it matches the correctly presented cut out 'B'. Then the diagonal mark is across, not with, the suggested fragment trajectory...

Edited October 28, 2006 by John Dolva

[Bernice Moore]

John & Tom :

A Question please...

I have been following this thread, and it appears to me that you are basing the Tague curb shot, trajectories with the Z 313 head shot, re the Zapruder film....from the TSBD..

But at the same time, Tom has posted previous information that the head shot occurred 30 feet further

down Elm Street, than what we see within that film....and John you agreed with his information, I believe.

If so. this study would therefore not be of any use, as the findings based on Z 313 would all be in error.

E.J.Hoover's report, was that this shot had not come from the TSBD, but from the Dal Tex or another

building....

Thanks B..

1. The first shot to the head of JFK was at Z313. (Second shot fired) Stationing 4+65.

2. The second shot to the head of JFK was some 30+feet farther down Elm St. in front of Mr. Altgens. (Last/third shot fired) Stationing 4+96.

3. The Z313 shot is the one that fragmented the bullet.

Bernice, thank you for your comments.

What I'm trying to do is to show what would happen to a fragment assuming it's from z313 wihout favouring the outcome. I think it shows that a fragment from z313 is unlikely if not impossible to strike the curb and if it did, is unlikely to cause the surface of the curb to break and send fragments to Tagues cheek.

I don't agree with Toms conclusions about the last shot, AND I don't disagree with them either, I'm following his explanations to the best of my ability.

Whatever, the method is really the important thing, and can be applied to any situation. Also I haven't had (I hope someone will) any confirmation (or denial) of the methodology. I already found one mistake (however that mistake when corrected made the curb strike even more unlikely). I have very little doubt that the mark on the curb is a curtate cycloid* wheel weight balance strike and it looks like the "blond Agent'# palmed a wheel weight and not a bullet. I know that wasn't in the same place, but the likelyhood, given the trochoids* on the small section of curb cut out and Tom's accounts from his youth et.c. makes no lead pieces collected and identified as wheel weights unlikely ie. >>>they were found, and for some reason not logged as what they were. I theorise that this is to confuse things and make the Tague strike credible because if it didn't strike the curb bur rather took the more credible downward trajectory to him, the fragment would have gone skipping across any number of vehicles behind him and there is no report of anything like that. IOW they needed it to rise up as a ricochet and the curb damage fitted the bill. Now subtract the Tague strike and the field is ripped wide open. No more 'but what about Tague?'. So it's important to get this right.

*

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********************

Thanks John:

I am also trying to follow both yours and his to the best of my ability, and when it comes to the trajectories

and such it does become a handful at times..

I realise that both you, I believe, now correct me if in error, and Tom believe perhaps only three shots from the TSBD

doing all the damage as reported to all involved..plus limo and such..and three shots only....

I try to keep an open mind in that area as I have never come to a final conclusion as to how many....there actually may have been.

Especially when I take into consideration

the witnesses information and first day statements, and first early reports, well there is great doubt....and as I put it they were present, and I was not.

Also, and cannot find it at the present time, when they cut and took the piece of cement curb finally, the

nick, hole whatever had been filled, touched off with a topping of cement, it had been filled...and when

Weisberg requested to see such, it had been destroyed, in that huge bulding there was not room enough

to keep a piece of cement and a possible shot strike to the curb.....

The following may be of interest to you....

This is from "White Wash" The report on the Warren Report....Harold Weisberg

1965...page 158-159..

About the curb hit...FYI,

Minutes after the assassination. Patrolman L.L.Hill radioed..

"I have one guy that was possibly hit by a ricochet from the bullet off the concrete." H 116.

James T Tague, had left his car at the end of Dealey Plaza opposite the Depository. He was slightly injured on the cheek and immediately reported this to Deputy Sheriff Eddy R. Walthers, 7H547,553.,

who was already examining the area to see if any bullets had hit the turf. Patrolman J.W.Foster ,on the Triple Underpass ,had seen a bullet hit the turf near near a manhole cover. Other witnesses in the same location had and reported similar observations, Walthers found a place on the curb where Tague had stood where it appeared a bullet had hit the cement ",

In the words of the Report .According to Tague ,"There was a mark quite obviously, it was a bullet ,and it was very fresh. "R 166.

Photographs of this spot were taken by two professional photographers who were subsequently witnesses in another connection. Tom Dillard had photographed the South face of the Book Depository Building. James R. Underwood, a television news director, had made motion pictures of the same area and had been in the motorcade.

From it's own records, the Commission did not look into this until July 7, 1964...when it asked the FBI to make an investigation which produced nothing. I discovered this entirely by accident, for there was no logical means by which to learn of it. What follows is a credit to neither the FBI nor the Commission:

Not until September 1st ,1964 with it's work almost done ,did the Commission call back Lyndal Shaneyfelt the FBI photographer, not a ballistics expert. Assistant Council Norman Redlich took a deposition from him beginning at 10.45 a.m. at the Commission's office. 15H 686-702

The previous investigation was reported in an unsigned memorandum of July 17, 1964, from the Dallas field office 21H 472 ff.

In it, the author politely called to the Commission’s attention that the photographs in question "had been forwarded to the President's Commission by Martha Joe Stroud, Assistant U.S Attorney, Dallas, Texas.".

In other words, if the FBI was going to be the subject to criticism for not finding what the Commission wanted, the FBI was going to have it on record that there was no need for the Commission to have delayed seeking further information.

This FBI report quoted Dillard as locating the point at which he took the pictures. It was, he said,” on the South side of Main Street about twenty feet east of the Triple Underpass." The FBI Dallas office said, “The area of the curb from this point for a distance of ten feet-in either direction was carefully checked and it was ascertained that there was no nick in the curb in the checked area, nor was any mark observed." In the concluding paragraph, repeating the above information almost word for word, the Dallas Field Office concluded," It should be noted that, since this mark was observed on November 23, 1963, there have been numerous rains, which could have possibly washed away such a mark and also that the area is cleaned by a street cleaning machine about once a week,which would also wash away any such mark."

Bear this in mind in considering what Shaneyfelt reported. Under the date of August 12, 1964.by courier service, J .E. Hoover presented the fruit of Shaneyfelt's investigation to Com. Counsel Rankin 21H 475-7.

Shaneyfelt had no trouble locating the spot. He used exactly the same raw materials the Dallas Field Office had used the two paragraphs.

What followed was all conjecture, and the most basic conjecture, supported by no evidence, was that all the shots came from the sixth-floor window. Thus, the FBI concluded that the shot would "correspond to frame 410 in the Zapruder film. " ...."and that it " went directly over the President's head."15H 699.

This was long after the President received the fatal wound that was the last shot according to the most credible witnesses.

Before supervising the removal of the curb and it's trasnportation to FBI in Washington on Aug 5,1964..Shaneyfelt took a number of photographs ,none of them with the possibility in mind that the shot could have emanated from any other source.

Perhaps the rains were light during those ten months or the street-cleaning machines inefficient, for there remained traces of the bullet. Spectrographic examination showed the metal smears on the curb were "essentially lead with a trace of antimony." This could have come from a mutilated bullet of the type presumed to have been used in the rifle. It could have come from a bullet of another type. Or it could have come from other sources .By "mutilated bullet" is meant one that deformed after first hitting another object. In his letter, Hoover precluded a bullet such as "from Governor Connally's stretcher " (he could not bring himself to say it was found there) or the "bullet or bullets" represented by the jacket fragments ...found in the Presidential limousine "He said" It was also determined from a microscopic study that the lead object that struck the curbing and causing the mark was moving in a general direction away" from the Texas School Depository Building". Hoover did not so state, but the bullet was also "moving in general direction away "from several other buildings, places and areas, such as the area where the puff of smoke was seen, or the building next to the Depository. If it were a fragment, he said, they did not know enough to determine "whether it was caused by a fragment of a bullet striking the occupants of the Presidential limousine, such as the bullet that struck the President's head. or whether it is a fragment of a shot that may have missed the Presidential limousine."

Politely Hoover was saying that there could not have been a fragment from any other bullet that hit an occupant of the Presidential car."21H 75-7

Even to ascertain that the thought that a fragment of the bullet that struck the President in the head could have gone this distance in this direction and left any kind of mark on the curb is to do violence to Euclid, whom the Commission has already left unchaste.......snip.

The point of impact of this "missed" bullet was well to the left and in front of the President .The President was also not turned in such a fashion as to make this possible, and the experts said that the only known fragmented bullet found, had it caused the President's head injury, dissipated it's energy in the explosion. The fragments did not have enough energy left even to carry them out of the car.

***************************************

Below is a copy from the DMN of the same photo you posted, but I believe may be a clearer copy, a close up of the hit,and a photo of possible other hits that day....may be helpful in your studies...

Thanks B.....

Edited October 28, 2006 by Bernice Moore

[Bernice Moore]

John:

Here is the Dallas Morning News photo that was taken and printed in their Newspaper..I believe..lightened, for you..

I do not see the marks or scratches on the curb.....were these scratches seen, made when the cutting out was done.I am thinking.....?????

B..

Edited October 28, 2006 by Bernice Moore

[John Dolva]

Tagues 'wounding' "He was slightly injured on the cheek and immediately reported this to Deputy Sheriff Eddy R. Walthers"

I think this is incorrect. I understand that Tague went over to where Walthers and others were and only after Walthers looked at him and pointed out blood on the cheek (a matter of droplets), Tague remembers a sting on the right cheek.

the mark on the curb: "Or it could have come from other sources" - and that one is the wheel balancing weight and its steel clip.

"What followed was all conjecture" - that's right and it has 'contaminated' all scenarios ever since.

____________________

("I realise that both you, I believe, now correct me if in error, and Tom believe perhaps only three shots from the TSBD doing all the damage as reported to all involved..plus limo and such..and three shots only...."

in error, yes as far as I go, I don't know where that belief comes from. Perhaps my willingness to discuss (almost) all scenarios seriously could have given such an idea. I've got a lot of respect for Toms careful fact based analysis'. I have such for many others and don't shirk from showing that. It doesn't mean I necessarily agree (or diagree) with all, or any of their conclusions.

My own studies lead me to believe the headshot came from the left, south of the limousine. I've gone over this in detail in the past and found no-one willing to discuss it, so no progress there. I'm more than happy to be shown wrong, and following 'opposing' viewpoints, like Tom's for example, may very well do just that)

Edited October 28, 2006 by John Dolva

[John Dolva]

"John: Here is the Dallas Morning News photo that was taken and printed in their Newspaper..I believe..lightened, for you..

I do not see the marks or scratches on the curb.....were these scratches seen, made when the cutting out was done.I am thinking.....?????

B.."

My apologies Bernice, I missed this post.

I looked at this in an earlier posting.

This shows the trochoids on the Dillard. I understand the curb was cut out quite some time later. As you can see on the top insert the trochoid pairs are just as they should be, IOW definitely from a rim scratching the curb. The Dillard has very poor definition in the lightened area, and it is taken obliquely. However, one can see that there are definite arcs in the surface. This means that such a curb strike by a rim is far from unusual. Also in another post I looked at scaling and the width of the curb damage and its location is the width of the steel clip of the weight and in the right height. As Tom pointed out this was the day of what we in OZ call 'conventional' ie non radial tyres. Jump to the posts linked to above and have a look. Look at Franks post and follow the link to see the gif of the trochoid scribing.

Edited June 4, 2007 by John Dolva

[Frank Agbat]

John,

Thank you for clarifying the graph. I didn't quite understand what I was seeing.

I've also looked in to the limo orientation on my own and I agree that a fragment would have to clear the front windshield at the very least. I was considering the possibility of a trajectory with declination and higher velocity, but this requires the projectile leaving the limo to exit from a side window, which doesn't go in the correct direction. So, we're back to 257-ish feet per second, 46 grains, and a curb...

Allow me to play devil's advocate for a moment... We need to consider conservation of momentum.

If the resulting curb chip has a mass less than 46 grains and the collision happened to be nearly perfectly elastic in nature, the resulting chip *could* leave the curb with a velocity greater than 257fps. If it happened to be sharp *and rotating* as it left, it seems possible that a slicing (almost paper-cut or shaving-cut style) wound could have been possible. So, my devil's advocate postulate is more of a "slice" than a classic projectile-through-skin concept. Thoughts??

(And on another note -- I'm rapidly coming around to the notion of a shot from the south. I wasn't ignoring your previous attempt to talk about it; I just didn't have enough background on the concept to discuss it intelligently.)

[John Dolva]

From a couple of sites that seem to explain momentum and elastic collisions:

"Momentum and energy are useful concepts because these quantities are conserved, that is, they do not change with time. You cannot create or destroy energy, you can only change it from one form to another [kinetic energy, potential energy, heat, acoustic energy (sound) etc.]. Likewise, you cannot create momentum out of nothing, nor can you get rid of it - you can only transfer it from one body to another. For instance, a traveling car has a lot of momentum. When the brakes are applied and the car stops, its momentum is actually transferred to the whole earth (through the wheels touching the road and through the air hitting the car) ! If the car strikes an unlucky pedestrian, then the car's momentum is partly transferred to the pedestrian and partly transferred to other things it comes in contact with, including the earth.

If a moving object collides with another object and the total kinetic energy of the two objects does not change - that is, it remains the same before and after the collision - then the collision is elastic. If some of the kinetic energy of the objects is transformed into heat or other forms of energy, then the collision is inelastic. Most collisions encountered in everyday life are inelastic. Notice that kinetic energy is only conserved in the special case of elastic collisions. In general, kinetic energy is not conserved. However, momentum is always conserved, regardless of whether the collision is elastic or inelastic."

"The amount of momentum that an object has depends on two physical quantities: the mass and the velocity of the moving object in the frame of reference. In physics, the symbol for momentum is usually denoted by a small p (bolded because it is a vector), so this can be written:

p=mv

where p is the momentum, m is the mass, and v the velocity.

The velocity of an object is given by its speed and its direction. Because momentum depends on velocity, it too has a magnitude and a direction and is a vector quantity. For example the momentum of a 5-kg bowling ball would have to be described by the statement that it was moving westward at 2 m/s. It is insufficient to say that the ball has 10 kg m/s of momentum because momentum is not fully described unless its direction is given."

I understand you are saying that the kinetic energy is conserved and none of it converted to sound or heat and all of it transferred to the chip of concrete? I'm really rusty on all this so if you could elaborate clarify etc please?

I imagine that for this trajectory that the horizontal momentum at the end (curb) is quite low and most of it is in the vertical?

Can you give a timeline of events with vectors and type of energy of fragment approaching the curved curb to where it leaves Tagues cheek? Both in the ideal and comment on the realistic?

Edited October 29, 2006 by John Dolva

[Thomas H. Purvis]

Tagues 'wounding' "He was slightly injured on the cheek and immediately reported this to Deputy Sheriff Eddy R. Walthers"

I think this is incorrect. I understand that Tague went over to where Walthers and others were and only after Walthers looked at him and pointed out blood on the cheek (a matter of droplets), Tague remembers a sting on the right cheek.

the mark on the curb: "Or it could have come from other sources" - and that one is the wheel balancing weight and its steel clip.

"What followed was all conjecture" - that's right and it has 'contaminated' all scenarios ever since.

____________________

("I realise that both you, I believe, now correct me if in error, and Tom believe perhaps only three shots from the TSBD doing all the damage as reported to all involved..plus limo and such..and three shots only...."

in error, yes as far as I go, I don't know where that belief comes from. Perhaps my willingness to discuss (almost) all scenarios seriously could have given such an idea. I've got a lot of respect for Toms careful fact based analysis'. I have such for many others and don't shirk from showing that. It doesn't mean I necessarily agree (or diagree) with all, or any of their conclusions.

My own studies lead me to believe the headshot came from the left, south of the limousine. I've gone over this in detail in the past and found no-one willing to discuss it, so no progress there. I'm more than happy to be shown wrong, and following 'opposing' viewpoints, like Tom's for example, may very well do just that)

And with your correct and proper method of application of reason and evaluation of factual evidence, I have little doubt that you will ultimately arrive at the same destination as I long ago arrived.

Your "posting" of card trick drawings appears to demonstrate that you are now fully cognizant of the "slight" sleight-of-hand tricks which were utilized to further confuse the issues.

Tom

P.S. You are also one of the reasons which I continue to provide whatever limited information I may possess.

[Frank Agbat]

...

I understand you are saying that the kinetic energy is conserved and none of it converted to sound or heat and all of it transferred to the chip of concrete? I'm really rusty on all this so if you could elaborate clarify etc please?

I imagine that for this trajectory that the horizontal momentum at the end (curb) is quite low and most of it is in the vertical?

Can you give a timeline of events with vectors and type of energy of fragment approaching the curved curb to where it leaves Tagues cheek? Both in the ideal and comment on the realistic?

Hi John,

Sorry for not replying to this sooner -- I had some chores to take care of.

I'm specifically saying that Kinetic Energy is not conserved. While Energy *is* conserved, KE is often not, as some is frequently lost in heat, sound, and various difficult-to-measure internal energy losses. I'm talking about the conservation of momentum, which holds for both elastic and inelastic collisions.

You are absolutely correct to point out that momentum is a vector quantity. Looking at a simple unidimensional model, conservation of momentum can be stated as:

m1v1 = m2v2 (m1 and v1 are mass and velocity of object #1, while m2 and v2 are the mass and velocity of object #2.)

So, if we know m1, v1, and m2, we can solve for v2.

v2 = (m1v1 / m2) or, to re-write: v2 = v1(m1/m2)

I was mentioning the case where m2 is lower than m1. In this case, the m1/m2 fraction is > 1.0, and the result is that v2 ends up greater than v1.

-----

So, in terms of the Tague scenario, it is possible that whatever struck Tague was very small (and possibly sharp) and moving very quickly, even though the maximum velocity of the lead curb strike was "only" 257 fps.

I put only in quotes, because it is only slow relative to the original muzzle velocity considered in the scenario. 257 fps is still moving at a pretty good clip (~175 miles per hour). I'm theorizing (as devil's advocate) that any of the following *could* have occurred:

a) the bullet fragment "splatted" itself, sending a small, but fast moving shard of itself across Mr. Tague's cheek, creating a cut.

the fragment impacted the curb, fragmenting a small portion of curb which cut Mr. Tague's cheek. The remaining portion of the fragment "bounced" off the curb, and is probably still out there somewhere

c) the curb hit, etc, are unrelated to projectiles, etc, and Tague was wounded in some other way

d) something completely different!

[John Dolva]

Ok, I get the momentum part now (I think). Though if we theorise a perfectly elastic collision, doesn't that mean kinetic energy is conserved? Anyway I get what you mean and if we are arguing for 'the devil' then lets assume so by all means, though the work done in separating a part of the concrete from iself would not be negligile? Momentum is conserved either way.

Also if it's a fragment of the fragment then isn't mv1 = Sum (m2v2+m3v3....?

The fragment then rises to a point 5 feet up and 20 feet across to Tagues cheek.

[Frank Agbat]

Ok, I get the momentum part now (I think). Though if we theorise a perfectly elastic collision, doesn't that mean kinetic energy is conserved? Anyway I get what you mean and if we are arguing for 'the devil' then lets assume so by all means, though the work done in separating a part of the concrete from iself would not be negligile? Momentum is conserved either way.

Also if it's a fragment of the fragment then isn't mv1 = Sum (m2v2+m3v3....?

The fragment then rises to a point 5 feet up and 20 feet across to Tagues cheek.

Hi John,

Correct -- a perfectly elastic collision DOES show conservation of Kinetic Energy. I wasn't necessarily theorizing on a perfectly elastic collision, but a simplified one dimensional collision.

My whole point was that just because the velocity of the bullet fragment may have been 257 fps, this doesn't necessarily limit a curb chip's velocity to 257fps or below... this is due to conservation of momentum. I still think you're on to something here --- I was just bringing up some possible counter points to consider.

[John Dolva]

OK, the threshold levels for beginning penetration at about 0.1 J/mm² for skin. and the distance to travel as above. 5 feet up 20 feet across. against gravity 32 fps.

Working backwards, what would be the correct figures for this fragment? As noone reported that a fragment skipped across the cars behind Tague is it reasonable to assume it had then sufficient energy to travers them all and end up somewhere down the tunnel?

Edited October 30, 2006 by John Dolva

[Frank Agbat]

OK, the threshold levels for beginning penetration at about 0.1 J/mm² for skin. and the distance to travel as above. 5 feet up 20 feet across. against gravity 32 fps.

Working backwards, what would be the correct figures for this fragment? As noone reported that a fragment skipped across the cars behind Tague is it reasonable to assume it had then sufficient energy to travers them all and end up somewhere down the tunnel?

John,

I wonder if the trajectory-plotting program you have would again prove useful here. Perhaps for initial considerations you could place the barrel at the curb and find the minimum muzzle velocity necessary for a fragment to travel approximately 20.61 feet. Just a thought...

But let's look at the 0.1J/mm^2. A Joule is one kg m^2 / s^2 (aka 1 Nm). So if we had a 3g object flying at 100 fps smacking poor James Tague in the face... let's see...

3g = 0.003kg

100fps = 30.48 m/s

KE = 1/2 mv^2 => .003(929)/2 = 1.39J

Which might, or might not be enough.. We're back to not knowing the shape or the orientation of what struck Mr. Tague... And herein lies the difficulty. Knives cut because they have a small contact area with the skin (fractions of a square millimeter), and if the alleged curb slice happened to be "sharp" the velocity required to cut might not be high at all...

[John Dolva]

This is so, Frank. Of course we must remember the size of the concrete damage and whether that is possible.

Did the FBI do a surface penetration test? If not one can perhaps find relevant tables. I've spent quite a lot of time looking for one but no luck so far.

Other considerations are

Carbonation: carbon dioxide weakens freshly poured concrete surfaces. This section of curb is in a low trough where one may expect a virtual sea of destructive gases. (does Dallas temps reach freezing?) Water can carry gas dissolved into micro cracks further weakening the surace.

A surface test is in order?

either it has been done and just has to be found

or

one could pump an airgun to 257 fps and shoot a weathered curb edge with a say 50 grain pellet and photo and post results. Best is probably shoot at a number of different pressures and photo and graph the results.

one needs to know that the concrete is of the same type etc as the 1960's dallas one

or:

2.3.2 Penetration test - This method is described in ASTM C 803. A driver,

usually powder-activated, delivers a known amount of energy to a steel pin.

The penetration resistance of the concrete is determined in place by

measuring the exposed length of the probes, which have been driven into the

concrete. This method measures the surface hardness of concrete and relates

to the strength property at a depth greater than indicated by the rebound

hammer method.

or take the curtoids as indicator of steel rim scratch test and relate that to a soft lead fragment.

[Frank Agbat]

John,

I think you're spot on. We need to research the materials side of things a bit more. I can certainly look into it, but I'm not a materials expert. However, I do know several people who are, and perhaps I can impose upon them for a quick tutorial...