February 19, 1886: Alexander Holder asked Holmes to find the missing part of the Beryl Coronet. [BERY]
February 19, 1886: Holmes followed the footprints that Arthur Holder and Sir George Burnwell made in the snow. [BERY]
February 19, 1886: Mary Holder eloped with Sir George Burnwell. [BERY]
Source
Information provided from the volume A Day by Day Sherlockian Chronology by William S Dorn DWNP, BSI.