Number Seven’s Son – An Irishman’s Diary about the cryptographer and friend of Joyce, John Francis Byrne

More than half a century after his death, John Francis Byrne has suffered the unusual fate that his name is now much less famous than his address. The former is remembered only by an initiated few. The latter is immortalised, at least in literary circles, as the home of James Joyce's fictional creations, Leopold and Molly Bloom.

Byrne lived at No 7 Eccles Street for a mere two years before emigrating to the US.

But crucially, it was where his old college pal Joyce visited him one day in 1909, in a state of utter distress.

Recalling the event decades later, Byrne said that although he had known his friend to be “highly emotional”, he had never seen him, or anyone, in such a “frightening” condition.


Joyce, he said, “wept and moaned and gesticulated in impotence as he sobbed out to me the thing that had occurred”.

As to what “the thing” was, even in a 1953 memoir, Byrne was still loyally discreet. We now know it was a rumour of Nora Barnacle’s alleged infidelities, about which Byrne was able to put Joyce at ease.

The grateful writer stayed for dinner, then for the night.

Mystic appeal

And just as his first date with Nora would become the day on which


was set, Number 7 Eccles Street became the home of the main protagonists.

Its importance as the scene of his deliverance from mental torture aside, the address would have had a mystic appeal for Joyce. It was a bonus that “Eccles” sounds Greek, in keeping with his theme.

But the number seven also has enormous resonance, from the biblical creation to the deadly sins. It’s the number (poetic or real) of the seas, heavens, continents, wonders of the world, colours of the rainbow, hills of Rome, and voyages of Sinbad.

So the house on Eccles Street would become one of the great (if now demolished) addresses of literature, long after its real-life occupant was forgotten. But numerology was to be a running theme for Byrne. And it was the tragedy of his life that his own genius for numbers did not win him the fame and wealth he thought it deserved.

One of the things he did in America, in 1918, was devise a system for encrypting text. It was both very simple and (he believed) unbreakable, using as it did two alphabets, a “right” and a “left” one, with an algorithm that, in substituting one character for another, became “chaotic”.

Hence Byrne’s name for the code, the chaocipher.

He likened its effect on text to the splitting of the atom. Yet it could be performed by a small, uncomplicated apparatus (his prototype used a cigar-box). With this, anyone could send messages readable only by the intended, and clued-in, recipient. Unlike Number 7 Eccles Street, there would be no entry without the key.

When Byrne showed his cigar-box invention to a cousin, she predicted it would win a “Nobel prize”. Nobels had been awarded for less, he agreed.

But alas, despite his assiduous campaigning, the US state department and other potential customers never took the idea seriously.

When he wasn’t championing the chaocipher, Byrne was a journalist, and a relatively successful one. He reported the 1916 Rising for Americans, and as a finance editor in the 1920s, appears to have predicted the Wall Street crash.

As the decades passed, he remained admirably quiet about his former friend, whose work had spawned an academic industry. But in 1953, he delivered the manuscript of his memoir to a Joycean scholar in the New York Times, who at first had no idea of his identity.

Joycean witness

After the visit, by chance, the NYT man was having lunch with Frank O’Connor, who told him excitedly that Byrne was the last important Joycean witness still in the wild, and that  the manuscript should be protected zealously, or Joycean experts would “tear you apart”.

Discussing his code in the book, ironically, Byrne speaks of mankind's age-old quest to communicate messages that are "wholly unintelligible" to all but initiates. He then jokes that certain writers may already have achieved this, although if he was thinking of Joyce and Finnegans Wake here, he heroically doesn't say so.

Elsewhere, there are many affectionate memories of their times together. But Byrne gives his own masterwork the last (encrypted) word. The memoir’s final chapter features a lengthy “translation” of text into the code. Readers are challenged to turn two lines back into English, for $5,000.

The prize was never claimed.