Painted on a 19th century building near the Spice Bazaar, this ghost sign promoted the business of tea merchant Issacoulian. It is written in Ottoman Turkish (using the Perso-Arabic script), Turkish using the Armenian script, and French. It certainly dates from the final decades of the Ottoman empire. At the time, French was the international language par excellence and was often spoken to overcome the language barrier between the many communities living in Constantinople. Relatively few people would have been able to read the part in Ottoman Turkish, which was used essentially for administrative and literary purposes by the elite of the empire. Its presence may suggest Issacoulian dealt with well-educated people. The majority of the Turkish population rather used the Armenian script, which was easier to read and write.
Unfortunately I have no information about Issacoulian and his business. The name would suggest he was a member of the Armenian community. Between the last decade of the 19th century and the beginning of the First World War, around 160,000 Armenians lived in Constantinople.
The upper part, written in Turkish Ottoman.
Immeditely below is the part of the sign in Turkish using the Armenian script.
Converted into Latin ortography, the name would read as "Isagoilean" but common spellings include among others Isagulyan, Issagolhian, Issagoulian and, as in the part of the ghost sign written in French, Issacoulian.
There may have been a fourth script but the lower part of the sign is too damaged to be able to decipher anything.
Location: corner Sultan Hamami Caddesi with Vakif Hani Sokak, Eminönü, Istanbul / Pictures taken in June 2011