In the dining room, Victoria is drinking coffee from a china cup. A second later, from another angle, she is cutting food on the plate - the cup is down.
The major accuses his subordinate of jumping on "the gravy train." The term "gravy train" came into existence in 1905, while the show is set in the 1870s. "Gravy train (1909) originally was railroad slang for a short haul that paid well."
When Maj. Eliot can't sleep and gets up his first night at the Barkley mansion he is seen wearing modern day paisley boxer shorts.