The Dusty Abacus

Avi Atias, my computer technician in Israel, has a small company called Abacus. The other day, I asked him how he came to choose the name.

“A friend suggested it,” he said. “I was looking for a word that wasn’t Hebrew and that had an international sound. But, hey, you’re the word man. What language does ‘abacus’ come from?”

Having no idea, I pulled out a dictionary and took a look. Then I chuckled. “What’s the joke?” he asked.

“The joke,” I said, reading from the dictionary, “is this: ‘Abacus. A manual computing device consisting of a frame holding parallel rods strung with movable counters…. [Middle English, from Latin, from Greek, abax, abak-, counting board, probably from Hebrew ’abaq, dust.].’ It looks like you gave your company a Hebrew name, after all.”

But why would our term for an ancient computing device come from a word pronounced avak in modern Hebrewthat means “dust” or “dirt”? An explanation is offered in my American Heritage Dictionary of the English Language, which sometimes accompanies interesting words with thumbnail histories:

“Originally, the abacus was, in fact, dusty…. The Greek word abax has as one of its senses ‘a board sprinkled with sand or dust for drawing geometric diagrams.’ This board is a relative of the abacus [that is] familiar to us.”

To be more precise, the ancient abacus, which probably was invented in Babylonia, worked on the same principle as does an abacus today, but it looked quite different. In its more refined form (for one always could improvise in any loose or sandy soil, which must be how the oldest abacuses originated), it consisted of a shallow box filled with sand. Instead of wooden or metal rods representing columns for ones, tens, hundreds, thousands and so on, vertical lines were drawn in the sand; instead of counters or beads sliding on the rods, holes were punched on these lines by a finger. Once a computation was finished, it could be erased by smoothing out the sand again in preparation for the next sum.

But even if the rod-and-bead abacus, which was invented only in the Middle Ages, was the sand abacus, why connect the latter with Hebrew avak? Although the ancient Greeks absorbed much science and technology from the Middle East, this came to them mostly through the Egyptians and the Phoenicians. Why would they have taken the abacus, or even just a word for it, from the Jews?

Indeed, some dictionaries also give as a possible etymology for “abacus” the Phoenician cognate of abak, which means “sand.” (Ancient Hebrew and Phoenician were closely related Semitic languages.) This would seem a more plausible derivation, were it not for a curious and generally misunderstood Hebrew phrase that we find in the Talmud.

This phrase is avak sofrim, literally “scribes’ dust,” and it occurs in a passage in the Mishnaic tractate of the Sabbath. In a discussion of whether or not writing is permissible on the Sabbath, we read:

“Writing with ink, with arsenic, with chalk, with tree gum, with copper sulfate, or with anything that leaves a [permanent] impression is forbidden…. Writing with beverage, with fruit juice, in ordinary dirt [avak drakhim], in scribes’ dust [avak sofrim], or in anything impermanent is permitted.”

What does “scribes’ dust” mean in this passage? If you look up avak sofrim in a Hebrew dictionary, you will read: “A powder scattered by ancient scribes on ink to dry it.” In turn, this is based on traditional rabbinic interpretations of the phrase, such as Rashi’s comment that it refers to “the powdered dust [afrurit] in a scribe’s jar.”

However, a moment’s reflection should convince one that this is illogical. If writing in ink is forbidden on the Sabbath because it is permanent, how could dusting the ink to dry it be permitted? This makes no sense at all.

Indeed, here “scribes’ dust” can mean only one thing: fine dirt or sand kept by a scribe, not in a jar to powder ink but in a box so that it can be used to write erasable and therefore impermanent words or sums. One can only assume that the 11th-century Rashi made such a mistake because by the time he lived, the rod-and-bead abacus had replaced the obsolete sand abacus.

And yet, if avak sofrim was the ancient rabbis’ technical term for the sand in a scribe’s box, it is perhaps not so unlikely that the Greeks took their word for abacus from it, after all — especially since we know of no parallel term from ancient Phoenician. It’s really not so hard to imagine:

An ancient Greek in Palestine sees a scribe doing sums by punching holes in sand and is impressed. “What do you call that?” he asks. “Avak sofrim,comes the answer. “Abak what?” says the Greek, who takes this ancient version of the computer back to Greece with him. “It’s an abak-something,” he tells his friends there, who cotton to the new invention, too. Pretty soon they’re calling it just plain abak and then abax, and before you can say “Avi Atias,” it’s the abacus we know.

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