Built in the late eighteenth and early nineteenth centuries, the Royal Canal connects the River Shannon with Dublin’s River Liffey. It is 90 miles long, has 46 locks and once did a thriving trade in barge traffic. By the late twentieth century, it had fallen into disuse and became a dumping ground, but it has since been cleaned up. Pleasure boats now navigate the canal, and its towpath is popular with hikers and bikers. Laetitia and her group hiked the towpath, starting in Drumcondra near Dublin and heading westward toward Mulingar, in County West Meath.

Near Binn’s Bridge is a bronze statue of poet and playwright Brendan Behan sitting on a bench. Behan wrote a poem/song called The Auld Triangle about Mountjoy Prison, which is on the canal. The song first appeared at the beginning and end of a 1954 play called The Quare Fellow that is set in the prison. Each morning the prisoners were awakened by the jangle of the triangle. Subsequently, the song has found its way into the repertoire of several Irish singing groups.

After hiking along the canal most of the day, the group stopped at a pub in Hyde Park. In Laetitia’s group were two students from Caltech. Sean was born in New York of Irish parents, and Mark was his friend from Chicago. Both were in physics and soon became known to the rest of the group as the nerds because they talked of little else. When the waiter arrived at the table, Sean asked for “three quarts for Mister Mark.” When the waiter looked puzzled, he said he was joking and ordered a Guinness.

When the waiter took the rest of the orders and left, Sean explained, “It’s just another bad physics joke, but it does have an Irish connection. Murray Gell-Mann, the Caltech quantum physicist who named the quark, got the idea from James Joyce. In Finnigan’s Wake, Joyce wrote, “Three quarks for Muster Mark,” an allusion to King Mark of the Tristan and Isolde legend. Gell-Mann chose the name because the entities that came to be known as quarks always occur in threes.”

The reaction of Laetitia’s group was mixed. Some thought Sean was clever; they had wondered about quarks and were pleased to know the origin of the name. Others thought it was just more nerd-talk and way more than they wanted to know about the subject. Laetitia was simply pleased to have an inspiration for the limerick of the day.

When Sean in a pub in Hyde Park
Said to bring three quarts for Mister Mark
Some thought him quite cunning
But he was just punning
James Joyce in good fun on a lark.