Truly a pioneer, the Stratoliner was the first commercial transport aircraft in service equipped with a pressurized cabin. In fact, Boeing just took their high-altitude proved B-17 heavy bomber main features and added a pressurised fuselage. As this TWA advertisement proclamed it was a real giant step in airline service. Sadly, first flown in Dec, 1938 World events soon overtook the possible commercial future of the Stratoliner. The seed was already sown anyway.
A pretty neat artwork, methinks.