Wallis was a semi-literate Cornish fisherman, a little mentally unbalanced and largely deaf, who took up painting at the age of seventy, never having received any tuition.
He painted largely out of loneliness, selling his pictures for a few pence to anyone who wanted them.
He died in a workhouse above Penzance at the age of eighty-seven.
Wallis used to paint old scraps of cardboard, most of them oddly shaped and supplied by the local grocer.
He insisted on using ship's paint, a medium which he understood, and he employed very few colours.
His subject was usually the sea and boats - scenes he had known during his early days as an Atlantic seaman and offshore fisherman.
Painting was for him a dip into the memories of the past.
Despite his lack of training, during his lifetime Wallis had a few distinguished patrons, for the most part artists, scholars and museum officials, among whom were Ben Nicholson, Barbara Hepworth and H.
S. Ede (then at the Tate Gallery).