I thought these were pretty cool pictures of two brothers posing on their BSA motorcycle with a blimp in the background. The best I can tell, the motorcycle is a Sloper model. The Sloper was produced from 1927 to 1935 and used a 500cc single-cylinder overhead valve engine. This model represented an important change in the geometry of motorcycles, as it had a much lower center of gravity due to the low seating position and use of a saddle tank (fuel tank that fits over the top tube of the frame). This layout influenced motorcycle design well into the 1960's. It also featured linked drum brakes that were operated by the foot pedal. The extra chrome and the year the picture was taken point to this being a 1930 year model. Wonder how they both made it to the middle of that field with only a solo motorcycle between the two of them...
The R100 is also an important part of airship history. Unlike the Sloper which was a precursor to the modern motorcycle, the R100 represents the end of British airship development. Making it's first flight in 1929, the R100 performed several successful trial runs as well as a two transatlantic flights from Britain to Canada. It was crewed by 37 men and carried 100 passengers. Powered by six Rolls-Royce Condor IIIB 12 cylinder 650 hp engines, it had a maximum speed of 81.5 mph. The range was an impressive 4,095 miles. The R100 was grounded in 1930 after another airship, the R101, crashed in France. A year later, the R100 was sold for scrap, ending the era of airships for the British Empire.