This picture is of a 20 H.P. Advance engine which blew up in South Central Pike County, Missouri near New Hartford and Olney, killing three friends; Bill Butler, Jap Trower, and Paul Prichett.
The explosion occurred early A.M. Had threshed about 50 bu. of oats, was firing with old rails. They were using a saw attachment which clamped on the drive wheel to cut off pole wood for fuel. Jap was using it. The explosion occurred so quickly no one seemed to see anything but a cloud of steam, but when it cleared up Bill Butler had the top of his head sheared off, Jasper Trower and an 18' section of fly wheel was found about 125 feet with Trowers body badly scattered about, and a drive wheel came to rest on Paul Prichett's head. Casper Prichett's son was sitting on the water tank and came out with only a foot injury; 3 killed, 1 injured. Front axle & wheels halfway to thresher, drive belt torn into 3 pieces, engine and gears, etc. stripped from boiler, engine blown back and turned almost half around. This tragedy occurred in July, 1921. My brother-in-laws 'Moran Brothers' bought the thresher, a Red River Special and a new N & S 20 H.P. engine in 1922 and as I had come back to Missouri from Oklahoma where I had been drilling during War I and after the blow up I tended separator for them 1922. We threshed in the same field and I looked the wreck over very carefully. The fire box was in good condition, safety plug in good condition, no series pits or flaws, stay bolts OK but lots of lime coating on flues, etc. In my opinion the flues having a heavy coating on them and firing with well seasoned rails probable red hot flues and the lime cracked, letting water to red hot flues causing the sudden pressure which no pop or safety valve could begin to take care of.
Bill Butler, owner of engine, was a well experienced thresher and saw man. Jap Trower firing and tending the engine was a good hand and experienced and they were threshing for Prichett who had just come in from the field and was getting a drink from a water barrel. I don't believe they knew what hit them.
I now live 200 miles from the place and have had my Nephew B.M. Elton gather data on the occurrence with the help of his Uncles Charlie Davis and Arthur Hays, who were there. They all live in that community.