The Chamber of Mines Research Organization (COMRO) was active for nearly 30 years, and developed a great many technologies benefitting the industry. It would be impossible to discuss all of these in detail – some selectivity was inevitable, and I have homed in on those that had (or in some instances should have had) the greatest impact on the development of improved methods for the mining of gold at great depths. As the book is an anthology, it is only as good as the technological, personal accounts, and related people stories provided by the contributors, and I am extremely grateful to those who participated. Many of them indicated that their time with COMRO was possibly the most rewarding and satisfying period of their professional careers. →