On leaving school he was employed as an apprentice draughtsman and engraver with Thomas Nelson, the publishing firm and printer in Edinburgh.

At the outbreak of war he joined the Royal Scots Regiment and was posted to northern France in 1915, serving in the Battle of the Somme.

On his return from Paris, the formal cubist influence of Lhote in Geissler's work softened and was transformed by his own observation of the geometry of the natural world.

He worked from close observation of nature, with scenes of lowland Scottish farms and farmsteads, of harbours with fishing boats, and of woodlands and trees.

His vision encompassed not only broad landscapes but was also enthralled by their finer details, as in Roots, Undergrowth, Toadstools, Dead Wood, Hemlock.

As if plants and trees were the representation of life, some of his works at the end of the Second World War create a haunting, sinister mood,[9] the expression of his desolation at the scene of a forest near Carrbridge felled by a storm.

References to some notable paintings not shown here are listed below, followed by a selection of some of his known works, arranged in approximate chronological order to show the development of his style and choice of subject matter during his career (see also [14]):