Picture via https://onlinebicyclemuseum.co.uk/1899-military-tandem-tricycle-with-maxim/ which also includes a cool story!

You gotta have those watt bazookas though to use your tricycle technical

Several prototype military tricycles and quadricycles were also adapted for carrying the Maxim, though the ensemble was invariably too heavy to move across rough ground and could only really be used on a road. The tandem tricycle illustrated below was built by Vickers Son & Maxim. It carried two machine guns hinged and mounted at the rear. 1000 rounds of ammunition were loaded into boxes mounted onto long ‘tripod’ tubes fitted to both sides of the tricycle; these tubes were hinged and when the machine guns were ready for firing they became braces to dig into the ground to hold the outfit in place. The weight of the tricycle plus guns and ammunition was 374lbs. It was too heavy to pedal up an incline (though it could be towed by other cyclists).

Especially considering 1901 is like a good bit before derailleurs would become common. This thing's a singlespeed in all likelihood.