Charles Piazzi Smyth (1819-1900) Joseph Black (1728-1799) David Brewster (1781-1868) John Napier (1550-1617) Decimal Point, Logarithms, Pocket Calculator David Douglas (1798-1834) Douglas Fir Gilbert Mallach (1881-1955) Multi-function Walking Stick Neville Maskelyne (1732-1811) Newton's Attraction of Mountains Charles Hutton (1737-1825) Mass of The Earth