Santos-Dumont's first flew around Paris in balloons with small petrol engines attached to the basket. His later balloons were of a 'semi-rigid' design, but just as dangerous to fly as they were still filled with hydrogen.
He used the no. 14, a ballon/plane hybrid, in an attempt to understand how to achieve controlled flight.
Santos-Dumont made the first 'hopflights' in Europe in 1906 in the 14-bis, the no. 14 without the balloon, and then achieved greater success with the Demoiselle monoplane in 1909.