What are unlimited solo machines?

Some articles on unlimited, solo machines, unlimited solo machines:

Brough Superior Motorcycles - Racing History (partial)
... Thomas, 2½ Miles Sprint for Unlimited Capacity Solo Machines, Cefn Sidan Speed Trials ... Thomas, 10 Miles for Unlimited Solo machines, Cefn Sidan Speed Trials ... Thomas, 2½ Miles Sprint for Unlimited Capacity Solo Machines, Cefn Sidan Speed Trials ...

Famous quotes containing the words machines, unlimited and/or solo:

    As machines become more and more efficient and perfect, so it will become clear that imperfection is the greatness of man.
    Ernst Fischer (1899–1972)

    God is a being of transcendent and unlimited perfections: his nature therefore is incomprehensible to finite spirits.
    George Berkeley (1685–1753)

    All mothers need instruction, nurturing, and an understanding mentor after the birth of a baby, but in this age of fast foods, fast tracks, and fast lanes, it doesn’t always happen. While we live in a society that provides recognition for just about every life event—from baptisms to bar mitzvahs, from wedding vows to funeral rites—the entry into parenting seems to be a solo flight, with nothing and no one to mark formally the new mom’s entry into motherhood.
    Sally Placksin (20th century)