It is loaded carefully. They are regular loads, loaded one behind the other in the same barrel. There is a separate ignition system for each load unless provision is made to move the ignition system to the touch hole for each load. In practice this technique was awkward, impractical and frequently dangerous. The leakage of hot barrel gas from one charge to another inevitably led to some or all loads igniting at once and the sequence could not be predicted meaning occasionally the load that ignited was obstructed by the load in front, exploding the barrel and possibly the shooter along with it. It was one of many, many experiments which tried to provide multiple rounds for the shooter without reloading. It was probably the craziest one ever invented and, given the technology of the time, was doomed from the start.
