Read the following passage and answer the questions given below.

Because birthday balloons are cheap and colorful, children like to buy and play with them. Balloons were first used for scientific experiments and transportation, but it wasn’t long before it found its way into people’s hands as an instrument of fun. Michael Faraday made the first rubber balloon in 1824, which was for use in his laboratory. Faraday achieved this by laying two sheets of rubber one on another, then put flour in the middle to prevent them joining all the way through and then sealed them together at the edges. Faraday found that upon filling the balloons with hydrogen, they were able to ascend to a considerable level, however he was disappointed by the fact that the hydrogen kept escaping. The following year, Thomas Hancock, a British inventor and rubber manufacturer, started selling balloon making kits. By 1847 British entrepreneurs were already selling the first balloons made of vulcanized rubber, which was tougher and was more elastic.