PETROGLYPHS - DIRECT VS. INDIRECT PERCUSSION REVISITED:

Hammerstone below petroglyph

panel, Wild Horse Draw, Canyon

Pintado, CO. Photograph 

Peter Faris.

On January 17, 2010, I posted a column on http://rockartblog.blogspot.com, Petroglyphs - Direct Vs. Indirect Percussion? In this I argued that most, if not all, petroglyphs had to be created by direct percussion and gave the reasons for this belief. I was recently informed by James D. Keyser of a paper that he and co-author Greer Rabiega published in the Journal of California and Great Basin Anthropology, 1999, Vol.21, No. 1, pages 124 - 136, entitled Petroglyph Manufacture by Indirect Percussion: The Potential Occurrence of Tools and Debitage in Datable Context. Keyser's comments concerning examples of indirect percussion are well reasoned and quite convincing, and are based on experiments reproducing fine or narrow lines on stone by striking a "chisel stone" with a hammer stone.

Rock art on boulder,

Airport Hill, St. George, UT.

Photograph Peter Faris, 2002.

Hammerstone on boulder,

Airport Hill, St. George, UT.

Photograph Peter Faris, 2002.

In his e-mail to me Keyser stated :

"I just look for the evidence, and where one finds very precise dints repeatedly aligned with one another to form all or part of a design the chances are that that design (or the very precise part of it) was produced by indirect percussion. Very finely made antlers (and other extremities) on small images of deer in Valcamonica rock art are a good example, but there are many others. Most often the examples of this sort of work that I can think of off-hand are small parts of  larger figures (but the entire figure itself is still not very large—say a deer that can be covered with a playing card)." (Keyser 2016)

"When a small part of a glyph occurs routinely (like the aforementioned Valcamonica antlers) without even one misplaced dint it begins to defy statistical probability that these were done freehand—when such a simple solution (indirect pecking) was available and can provide a guarantee that no dint will be miss-hit. If such finely produced antlers were relatively rare—so that there were a few of many that had no miss-hit dints, then one could argue that the very precise ones were simply normal variation, but when one sees dozens of examples of such deer at site after site—all of whom have antlers, legs, hooves, and open mouths—with nary a miss-hit dint in the bunch—a student must begin to look for a way that this was done that essentially “guarantees” accuracy EVERY TIME THE STONE IS STRUCK. Indirect percussion is the only means by which this can be accomplished (with such a guarantee) that I can come up with....I’d be glad to know." (Keyser 2016)

Hammer stone used with chisel

stone in experiments showing

evidence of impact with the chisel

stone on its side. (Keyser , James

D., and Greer Rabiega, 1999).

I am actually more convinced by what he did not find than by what he did. Keyser reports large numbers of fine lines in petroglyphs with no evidence of the mis-strikes that one would expect to find if only direct percussion had been used to produce them. Now this is a telling argument and I take it very seriously as I have to agree with Jim that the lack of missteps is suggestive of an accuracy very difficult (I am sure he would say impossible) to achieve with only direct percussion.
I do feel compelled to note, however, that this paper and communication are both about an experiment, and that he has not yet reported finding such chisel stones. Admittedly, there has probably been little awareness of their possibility so no one has looked for them. Also, Keyser also commented that as they are smaller and lighter than the hammer stones they may have regularly been carried away as useful tools, not dropped in the ground when the petroglyph is done as so many hammer stones were, " that’s the beauty of a chisel stone—you can carry two or three dozen of them with the same weight as a single good-sized hammer stone." (Keyser 2016)

Bird Rattle carving petroglyph,1924,

Writing-on-Stone, Alberta, Canada.

Blackfoot.

I am enclosing this picture of Bird Rattle producing a petroglyph at Writing-on-Stone, Alberta, Canada, in 1924, as it is the only illustration I could find of petroglyph production in an authentic context. It really does not apply to the question here, however, as this petroglyph was produced by incising, not by pecking, so the techniques under discussion were not used by Bird Rattle.

Bird Rattle carving petroglyph,1924,

Writing-on-Stone, Alberta, Canada.

Blackfoot.

Note: until such a chisel stone is reported in context at a petroglyph site this is all conjecture based only upon logic and his reported experiments, but then my original statement was also. Remember, the absence of proof is not proof of absence. So, thank you to Jim Keyser for his information and help. I appreciate that you took the time to help me clarify this question. Correction noted Jim, and thank you. I will temper my opinion accordingly. 
And I also must confess that I have never examined the fine lines in a petroglyph for this phenomena, superimposition yes, mis-strikes no. So in the future I will have another line of evidence to look into. 
Those who would like to dig a little deeper into this example are referred to the 1999 paper by Keyser and Rabiega, cited below.

REFERENCES:

Keyser, James D., personal communication, May 7, 2016.

Keyser , James D. and Greer Rabiega,

1999,  Petroglyph Manufacture by Indirect Percussion: The Potential Occurrence of Tools and Debitage in Datable Context, Journal of California and Great Basin Anthropology, Vol.21, No. 1, pages 124 - 136.

PETROGLYPHS – DIRECT VS. INDIRECT PERCUSSION?

It seems to be almost universal that people writing about petroglyphs assume that they are produced by indirect percussion – the use of a hammerstone to hit some form of chisel which carves the image into the rock surface. I have even seen a number of artist’s impressions showing a Native American holding some form of chisel against the cliff with one hand and holding the hammerstone in the other hand. Just a little reasoning tells us that this cannot possibly be correct. If such a stone-age culture wanted to build a chisel they would have to use a sharpened stone blade with a bone, horn, or wood shaft, assembled with lashings and possibly low quality natural adhesives.

Newton’s second law of motion (conservation of momentum) tells us that as much or more of the force from pounding on such a chisel with the hammerstone would be absorbed by that chisel than would be transferred to the rock surface. This technique would very quickly destroy the joints in the chisel leaving the rock surface essentially untouched (if the rock surface is soft enough, a deer or elk antler tine used as a chisel, a hard, tough material which would probably be successful because it would have no joints to fail under repeated impacts).

Bird Rattle carving petroglyph,1924, Writing-on-Stone,
Blackfeet, from James Keyser,Art of the Warriors
Univ. of UT Press, Salt Lake City.

It is obvious to anyone with any firsthand experience in carving stone and the required tools, that petroglyphs must have been created with direct percussion – hitting the rock surface directly with a harder hammerstone. Indeed I have found many of the hammerstones used to create petroglyphs lying on the ground at the base of the decorated rock or cliff. People with no first-hand experience generally assume that direct percussion is extremely difficult, requiring heavy blows, and that accuracy is very hard to achieve. This is, in fact, incorrect. Moderate, easily controlled blows are best, and they can be applied with considerable accuracy.

We must remember that much of the great stonework of the ancients was created in exactly this way. Egyptian stone for temples, pyramids, and obelisks was quarried from the bedrock by pounding with hammerstones. Mayan and Aztec architecture was created by pounding with a hammerstone, as was the cyclopean stone work of the Incas. Indeed, the multitude of Easter Island statues were quarried and carved with direct percussion of a hammerstone. With all of these marvelous examples why do we still question the ability of direct percussion to create the petroglyphs?

Hammerstone below petroglyph panel,
Wild Horse Draw, Canyon Pintado, CO.
Photo: Peter Faris.

I think it is because our image of carving stone comes from Hollywood style presentations of Michelangelo carving large blocks of marble with a swinging mallet and a chisel. Metallurgical technology has given us chisels made from tempered steel that can hold up to the repeated blows of the mallet and to the surface of the stone. Our cultural technological focus tends to carve with the indirect percussion of a hammer or mallet and a chisel. We have a cultural bias toward expecting the use of a chisel in carving a hard substance.

Native American Rock Art, Yvette La Pierre,
1994, Thomasson-Grant, Charlottsville, VA.,
illustrations by Lois Sloan, p.22

There is a marvelous book for children about rock art. Native American Rock Art, by Yvette La Pierre, 1994, illustrated by Lois Sloan, has two nicely painted illustrations in it which show the creation of petroglyphs correctly using direct percussion. The irony in this is that they have it correct while so many experts get it wrong. Perhaps La Pierre and Sloan are actually the experts in this. Well, with this book to show them correctly the children growing up to be the next generation of rock art experts may get it right.