This paper describes the rise and fall of a self-made mining magnate. After a poor education, Henry Hopper Adams first became involved with mining, at Thames, when almost 17, although he later gave an even younger age. He quickly learnt the basic skills of mining, and by 1875 was a mining company director and in the late 1870s erected and managed batteries in addition to erecting bridges and water races; although describing himself as an engineer, he was an untaught one. Having participated in the Te Aroha rush, he supervised the erection of its battery and then erected the first one at Waihi. Neither were successful, the former because of the absence of payable gold and the latter because of insufficient water power. At Waihi he made the first of many modifications to the machinery used in treatment plants. At Waiorongomai he erected the battery, water races, and tramway, but as the Battery Company that employed him gained increasing control over this field he was subject to frequent criticism for decisions that were outside his control. As the field declined, he managed more and more mines on behalf of this company. As a leading figure in the Waiorongomai community, he did his best to assist it and to improve the battery. A visit to America to investigate new techniques led to his facilitating the purchase of the battery and many of the mines by the Te Aroha Silver and Gold Company, for which he worked as general manager for a time. When this company abandoned the field, he acquired its property in 1890, being confident that the district would produce payable ore. As well as owning the Waiorongomai battery and most of the mines, he diversified by also owning a timber mill, flax mills, and farms. Adams was the first man to trial the new cyanide process at Waiorongomai, starting with the tailings plant in mid-1892 and then the modified battery itself in that December. Despite the modifications he made subsequently, cyanide was not a success because of the presence of copper in the ore, and in 1894 the plant was moved to Karangahake. These unsuccessful ventures prompted him to seek financial assistance from the government. After leaving Waiorongomai in mid-1895, he managed mines and erected and managed batteries throughout most of Hauraki, becoming one of its leading mining figures. By the early twentieth century his efforts were focused in particular on Broken Hills (near Tairua) and Thames, where he tried to introduce large-scale developments, especially in its deep levels. He was assisted by a group of business associates, many of whom were friends, and who would not benefit by sticking with his increasingly unprofitable ventures. Having earlier accumulated considerable wealth, by the end of his life all his money had gone.