The article observes language and professional features of author's personality appearing in non-fictional texts. Notes of the XIX century travellers are the unique evidences of the epoch when intensive scientific activity was accompanied with the formation of the language for scientific description. Such details as language units of different functional usage, peculiarities of text formation and features of comments making together with the ways to mark the author's point of view are being analyzed as the signals transmitting additional information about authors of the texts. It allows making a conclusion about author's cognitive base and about the level of the author's involvement into the process of data transmission to the professionals and into the process of the scientific language creation.