The practice of locating natural gas and petroleum deposits has been transformed dramatically in the last 20 years with the advent of extremely advanced, ingenious technology. In the early days of the industry, the only way of locating underground petroleum and natural gas deposits was to search for surface evidence of these underground formations.
Thumb Safety. No, the problem with a Thumb Safety is it's a Minor Motor Skill the way your brain see's it. Under a stressful situation you may loose all minor motor skills. All my guns I train with and I train consistantly, do not have any safeties.
Note that when in the safe position, the safety lever is forward and up - the same as the second type safety, the New Safety, and the Universal Safety. When this Joint Safety appeared, production C-96s had the first type safety - a short travel arc, on safe when the safety lever was pulled down. So the Joint Safety was an early attempt by Mauser to make a safety which worked somewhat like the later production safeties.