Methods of representing mechanical constructions in the journal 'Izys Polska' (1820-1828)

'Izys Polska' (Polish Isis) was one of the first Polish technical journals. It appeared in the years 1820-1828, under Gracjan Korwin - its first editor-in-chief and then Antoni Lelowski who took over after the death of Korwin. The subject-matter of the journal was very broad: the topics that were most frequently dealt with included farming, the food industry, and animal husbandry. There were also articles concerning other branches of industry, such as the steel industry. The journal also published articles describing steam engines, lifts, methods of gear generating as well as articles on building and on applied art. The authoress analyses the journal's rich illustrative material with regard to how constructions were represented in it.. The source material for the study is made up of eighteen volumes of the journal, with four issues per volume, i.e. a total of 72 fascicles. The paper analyses methods of projection, the kinds of projections used and scales of drawing used. The figures published in the journal most frequently involved the use of orthogonal projection, with central projection being the least frequently used. Both views and sections were used, and one of the figures depicts a semi-view/semi-section, which must be seen as a significant step in the development of visualization methods. Another element that was significant in the development of constructions was the frequent use of scales in the figures.