Öz The object of this article is to draw attention, again, to the dravvings of the Swedish officer Cornelius Loos, who spent one and a half year in 1710-11 in Turkey dcpicting interesting monuments. Unfortunately most of the maıcrial was dcsiroyed by fire, but at least the complete set of dravvings from İstanbul seem to have been saved. Some of them have appearcd in scholarly discussions, such as the fine and rare drawings from the intcrior of Ayasofia. They play a certain röle in the publications by C.Mango in his discussions of the mosaics of the church, published in the Dumbarton Oaks Papers 1962 and 1966 and elsewhere. A few more items are observed by ot her scholars, but as a whole the material has been neglected. This is due more than anything else to the lack of a good and comprehensivc publication in an International language from Swedish side.