In 1880, as "J. J. H. Leonard", he won a prize for an
India ink drawing, and after finding a ready market for his pen-and-ink sketches, caricatures and lithographs (as "Leo") in the
Port Adelaide News,
The Lantern,
Adelaide Punch and ''
Frearson's Weekly, he felt sufficiently confident to quit his job and became chief cartoonist for The Lantern'', which at that time boasted a fine stable of artists:
A. S. Broad,
J. H. Chinner,
Alfred Clint,
H. J. Woodhouse,
James Ashton and
John Hood. He established an upstairs studio in
Flinders Street. Leonard had other talents: he was a capable light tenor, and an actor, one of the more successful players in
H. J. Woodhouse's short-lived Yorick Club of amateur thespians, providing additional entertainment with "lightning sketches" of local celebrities when they played at large towns such as Kapunda and Gawler. In 1886 he left Adelaide to take a position with
Melbourne Punch. In 1888 he famously exhibited, in a
Bourke Street shop window, an oil painting satirizing the
free market champion
Henry Parkes as
King Lear with the dying
Cordelia (representing the NSW economy) in his arms. A similar cartoon, reportedly published in
Melbourne Punch, has yet to be found. He moved to Sydney, and by 1892 was employed by the
Illustrated Sydney News. Leonard was particularly virulent in his denunciation of the bankers who closed their doors in the
1893 banking crisis. as proprietors of a Sydney publication named
Police News, were tried for criminal libel, but the Attorney-General declined to prosecute.
Some works "The Mirror", a wine bar in
Rowe Street, Sydney, was decorated with hundreds of his sketches of well-known people. Leonard's drawing
Soldiers of the Queen, of men in various uniforms, in
The Australian Field of December 1900, was the first colored artwork published in an Australian newspaper. He illustrated, as "Leo", "A Vagabond"'s 1877–78 five volumes of reminiscences with a portrait of the author,
John Stanley James ("Julian Thomas"), on the frontispiece and line illustrations throughout. These illustrations were carried through to the single volume condensed version, • . As a challenge, or proof of his skill with the pen, in 1901 he drew a portrait, on card, of the
Duke and Duchess of Cornwall and York, surrounded by Australian wildflowers and the representation of an ornamental frame, all consisting of one line only, without a break or crossing, and of varying width to create light and shade, commencing at the tip of one nose and terminating at the other. Quite apart from its value as a demonstration of penmanship, it was said to be an excellent drawing. It has been suggested that the cartoon "He got 'em again" published in
The Brisbane Worker in 1906, was by Leonard. The signature at the lower right corner is an interlocked "JL". He was also known for creating
illuminated addresses. Recipients included: • E. Kidgell, sub-editor of
The Sunday Times • H. M. Evans, managing director of the publishers of
The Sunday Times,
The Referee, and
The Arrow. • Mr Bates, stationmaster at
Mortdale • Presentation at St George's Hall, Mortdale, to Dr. J. Eli Webb and nurses Palmer, Bantin, Bastin and Grattin for their work i the 'flu epidemic of 1917–20 • W. I. Donald, Town Clerk, of
Hurstville, who had returned from the war. • Presentation at the Masonic Hall, Hurstville, to ex-alderman Hugh Patrick. Some, perhaps all, of these were produced
gratis, out of respect for the intended recipient. ==Family==