Grammar girl here. Last year I heard on NPR that the Museum of Modern Art had

acquired the AT symbol for its Department of Architecture and Design Collection

and that got me interested in the origin of the symbol. Every source I found

seemed to have a different date for the origin of the AT symbol so I'm not

going to commit to a certain date. Let's just say it was a long time ago at least

in the middle ages. Many sources including the Ask Oxford website and a book

called Letter by Letter, an alphabetical miscellany, reported that the AT symbol

comes from shorthand for the Latin word ad, ad, which means two toward or at.

Scribes used it to list prices on invoices and accounting sheets as in 12

eggs at one pence per egg. The AT symbol by the way is more formally known in

English as the commercial at, presumably because of its original use in

commerce. It has various names in other languages and one of my favorites is

Italian in which it's playfully called the snail. Long time listeners or

people who have my books will know that in my example sentences I like to use a

character called squiggly who's a snail. I've also seen the AT called a

strudel or a cinnamon roll which are both cute because it is kind of shaped like a

rolled up pastry. Describing how we get from the Latin word ad to the at symbol,

Michael Quinnian explains on his website Worldwide Words that when the symbol

was written by hand, I believe by scribes in the Middle Ages, quote,

the upstroke of the D curved over to the left and extended around the A.

Eventually the lower part fused with the A to form one symbol, unquote. So that

circle around the A is actually a remnant of the tall part of the letter D. A

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