Arnold was educated at Kilmarnock Academy; at Oldham Grammar School; and at Bootham School, York. He became a member of the Surveyors’ Institute, and was employed in the Land Valuation Department. He volunteered for active service, enlisting in the R.A.M.C. in June 1915, he entered the war in the Balkans on 15th November 1915. He died in Salonika of pneumonia, and was buried in Mikra Bay Cemetery. His Commanding Officer wrote: “I have been his Commanding Officer for ten months, and have nothing but praise for him in every way. I always found him most hardworking and reliable. I am afraid his keen sense of duty may have been contributory to his death. He was a great favourite with everyone in the unit.” Arnold was the son of Thomas Simkin and Amy (daughter of Charles Rawbone of Stockton) Jennings, of Sonnenberg, Middlecave, Malton, Yorks.