42:40 · These are pictorial signs for comets. In alchemy they have been used to denote gold although gold was usually represented with the sun sign .
    According to Diderot's Encyclopedia these signs were used to denote glass in France in the eighteenth century.
    In modern military contexts stands for searchlight.
    Due to the fact that comets are rare occurrences, these and similar signs have also been adopted and used in dictionaries and lexicography in general to mean that a word is rarely used.