Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Stufenkeil zur Feststellung der richtigen Belichtungsdauer fuer Papiere und Diapositive und zur Feststellung und gegenseitigen Abstimmung der Haertegrade von Negativ undPositiv
Report Addressed to the Marquess Wellesley, Lord Lieutenant of Ireland, by Elizabeth Fry and Joseph John Gurney Respecting Their Late Visit to that Country