Boart Longyear Longyear, which eventually became Boart Longyear. He drilled his first diamond drill core hole in 1890 in northern Minnesota. Longyear's company developed the wire-line retrieved Q core barrel. Longyear was inducted into the National Mining Hall of Fame in Leadville, Colo in 1990. On March 1, 2016, Mr. Jeffrey Olsen was appointed President and Chief Executive Officer of Boart Longyear. He joined the company as the Chief Financial Officer in March 2014. Boart Longyear conducts contract drilling services in more than 40 countries, and provides mining products to customers in over 100 countries. Boart Longyear Boart Longyear is a global
Léon Teisserenc de Bort an indication of a temperature inversion or at least of a zero lapse rate above this altitude. For many years he was uncertain whether he discovered a true physical phenomenon or whether his measurements suffered from a systematic bias (indeed, the first measurements "did" have a positive temperature bias as the instruments were liable to radiative heating by solar radiation). That is why Teisserenc de Bort carried out 200+ more balloon experiments (with a substantial part of them being held during the night to eliminate radiative heating) until 1902, when he suggested that the atmosphere was divided into two layers.