William Evill is listed as a Manufacturer of Mineral Waters lived at "Bushey House" in Streatham Hill with his wife Mary, 6 children and 5 servants. He was also a Silversmith and born in Bath.
William Evill and Kemp-Welch took control of Schweppes in 1834 and immediately set about growing it further.
In 1835, they launched an artificial seltzer water – to be drunk straight, or with a little milk, wine or syrup – and also marketed the first aerated lemon- ade. This was the first and only sparkling fruit drink produced by the company until much later when an orange flavour was added in 1931.
Shortly before the Great Exhibition in the Crystal Palace, in Hyde Park, London, the duo opened another factory in Liverpool. The additional factory was vital because what followed the Great Exhibition was unexpected. Welch and Evill paid the princely sum of £5,500 for the privilege to sell their drinks at the largest exhibition of its time. During this period, Schweppes sales ballooned to 88,800 dozen and grew by a further 47% over the next two years. After the Great Exhibition, where 1m bottles were sold, sales rose to 192,000 dozen.
Spurred on by their success at the Great Exhibition, Welch and Evill launched a factory in Glasgow, then one in Sydney and another in New York. During this period, the duo also launched the first Indian tonic water and a ginger ale.