Kjellén's Blanket: Methods of a Rock-Art Master Surveyor

i-01700146f226279fcf0ac28c284eea68-slapljus.jpg

Roger Wikell, Kenneth Ihrestam and Sven-Gunnar Broström during a recent documentation session with oblique lighting in Småland. Photograph by Emelie Svenman.

Many important categories of archaeological site are never discovered by academic archaeologists. In the case of wetland sacrifices, it's simply because nobody's figured out a method to look for them. We just have to sit around waiting for decades until one turns up in the course of some unrelated activity. But in most cases, our problem is actually that we aren't good enough at the methods that exist, simply because we don't spend enough time doing them. I'm thinking of field walking, metal detecting and rock-art surveying. The masters of these methods that I have worked with have all started out as hobbyists, even though a number of them are now recognised professional specialists.

The basic reason for this is probably that few people, including academic archaeologists, want to spend their weekends doing what they do at work. And nobody gets paid to put in the hundreds of hours it takes to get really good at field walking, metal detecting and rock-art surveying.

Yesterday I attended a seminar to the memory of one of the greats in Swedish rock-art surveying: Einar Kjellén (1903-2000). He was a farmer's son and an auctioneer, and he happened to live in the Lake Mälaren area's greatest cluster of Bronze Age rock carvings around the town of Enköping. Or, perhaps it is more accurate to say that he almost single-handedly created that cluster. Because although others were moderately successful in the vicinity, Kjellén worked almost entirely in four parishes and found hundreds of sites there. We don't really know what's outside his action radius.

Finding rock carvings is largely a question of vegetation and lighting. You need a stout brush and oblique single-direction light to bring out the often very shallow pecks and grooves in the rock. Yesterday, Kjellén's daughter told us about one of his forgotten methods. Asked what the landowners thought of him, she replied that he was a well-known and respected figure thanks to his day-job, "But of course, some thought he was a little crazy, crawling around like that with a blanket over his head". Most of us didn't know what she was talking about.

For most of a Swedish summer day, there is no oblique light. It's almost vertical and also diffuse. But Einar Kjellén had discovered that all he needed to get a patch of good light on a rock-art panel was the picnic blanket he kept in his car. You lie down on the panel, put the blanket over your head and lift one edge of it ever so slightly. In streams oblique light even at noon. To move the light source, just lift another part of the blanket's edge. As Douglas Adams wrote, you need to know where your towel is.

[More blog entries about , , ; , , , .]

More like this

I like the blanket trick. Low-tech and practical.

The way we find dropped small parts is to roll a flashlight along the floor. The light reflects off the part and/or the part creates a long shadow. A small 2-AAA LED flashlight works great. I slightly modify mine by wrapping a rubber band around the butt end to correct for the taper of the flashlight body so that the light is more in line with the floor.

An interesting variation might be to use a colored LED so the oblique light would strongly contrast with any ambient light. A green LED might be ideal given the sensitivity of the eye to that color.

I wonder if any inscriptions might show up better if you had one color of light coming from one direction and a second color oriented perpendicularly. Say Red and green LEDs. If nothing else, the lighting would be festive.

You might combine the blanket with a couple of small LED flashlights and see how it goes. Find a spot you wish to sketch or photograph and you can use putty or blu-goo to hold the flashlight/s in position.

Seriously gooey ;)

Good idea, I will test it as soon as I have the time.

By the way, someone that saw "Vetenskapens värld" on Swedish TV recently? They had an entry about rock carvings in Bohuslän and Val Camonica.