The article presents the problems of building and maintaining urban transport infrastructure in Warsaw at the turn of the 20^th century. The text concerns Kajetan Mościcki (1855–1933), engineer, who was appointed by the acting Mayor of Warsaw, General Sokrates Starynkiewicz, to the position of senior city engineer and head of the municipal construction department, where he worked from 1889 to 1909. During this period, he paved the streets which were worn or damaged by sewerage works with wooden blocks and covered the sidewalks with concrete slabs. He designed the first slip road in the Kingdom of Poland in the form of a spiral, and he also participated in the construction of the oldest road engineering structures made of reinforced concrete, located in Ujazdowski Park and on Karowa street in Warsaw, the first Warsaw power plant and the second city bridge across the Vistula. In addition to his professional activity, Kajetan Mościcki was an inventor in the fields of mechanics and electrical engineering. At the end of his life, he founded an award that the Polish Academy of Arts and Sciences was to grant to Polish scientists for outstanding achievements.

In 1907, Stanisław Zakrzewski (1873–1936), one of the most outstanding Polish historians of the interwar period, created a seminar on Polish history at the University of Lwów which prepared students for further research on the history of the Polish state of the Piast and Jagiellonian times. During the time the seminar was active (1907–1936), forty participants took up systematic scientific research. The students adopted their mentor’s approach to research and presented similar views on particular historical phenomena. They were also connected with Zakrzewski by a unique emotional bond, which lasted not only during their studies and preparation of doctoral dissertations, but even after they had reached scientific maturity.

The times of the Second Polish Republic were a particularly important period in the development of Polish archeology, because after Poland regained independence, the first state institution was established to organize the protection of archaeological monuments throughout the country. It was the State Group of Prehistoric Monuments Conservators functioning in the years 1920–1928. Their activities in the Kielce voivodeship brought particularly interesting results. Conservators and delegates of the State Group of Prehistoric Monuments Conservators did a lot in the field of inventory and protection of archaeological monuments in the Kielce region, undertaking surface and excavation rescue research, as well as popularizing archeology among the inhabitants of the region. The result of their activities was the registration, discovery, and exploration of many archaeological sites, including such valuable ones as a complex of multicultural sites in Złota near Sandomierz and in Książnice Wielkie, and a unique complex of striped flint mines in Krzemionki near Ostrowiec. The sites discovered at that time in the Kielce voivodeship are still the subject of interest and research to Polish archaeologists.

The article presents Wilhelm His Sr.’s (1831–1904) methodological path of research in the field of neurophysiological foundations, explained through specific mechanical causes. In this research context, the scholar searched for the so-called fixed cause-and-effect principle, which refers to the targeted development of the nervous system. His’s pioneering research mainly focused on the structural genesis of the nervous system and the growth and development of embryonic neural cells.

The article is devoted to a project carried out after the Second World War by historians of science whose aim was to explore the world heritage of historical scientific instruments. The article presents the results of research whose purpose was to learn the methods of implementation and the results of compiling an inventory of historical scientific instruments preserved in Poland after World War II.

The Commission pour l’inventaire mondial des appareils scientifiques d’intérêt historique (the Commission for the World Inventory of Scientific Instruments) was founded in 1956 at the International Union of History and Philosophy of Science in Paris – the Division of the History of Science. The aim of the Commission was to coordinate work on the implementation of a world inventory of historical scientific instruments. The concept of the inventory card was prepared, and the criteria for the selection of historical instruments for the inventory and deadlines for the project were set. Members from at least 29 countries participated in the works of the Commission. The project was implemented by European science and technology museums and national academies of sciences. The collected data was recorded on index cards which were prepared, among others, by French, Italian, Belgian, Czech, and Polish researchers. A Russian catalogue was published. In Poland in 1959–1963, work on the inventory was conducted by the Department of History of Science and Technology of the Polish Academy of Sciences. Queries were commissioned to Tadeusz Przypkowski, a science historian, collector, and expert on gnomonics. For the world inventory, he selected about one hundred of the most valuable science objects from the collections of Polish museums and other institutions. Nearly 20% of those were gnomonic objects, the remaining part consisted of astronomical instruments, pharmacy instruments and individual objects pertaining to other fields of science. Works on the national inventory of historical scientific instruments were also carried out under the guidance of Przypkowski. The preserved documents do not allow us to determine at what stage these works stopped. Currently, the project ‘National inventory of historical scientific instruments’ is being implemented at the L. & A. Birkenmajer Institute for the History of Science of the Polish Academy of Sciences. It aims to create an electronic database of historical scientific instruments which have been preserved in Polish museums. The project has been financed by the National Science Centre Poland (Research project: OPUS 13 No. 2017/25/B/HS3/01829).

Ignacio Bolivar, one of the most prominent entomologists of the 19^th and 20^th centuries, the Director of the National Museum of Natural History in Madrid, corresponded with naturalists associated with the Zoological Cabinet in Warsaw. The collection of the Museo Nacional de Ciencias Naturales contains the letters of Władysław Taczanowski, Ludwik Dembowski, and Ludwik Młokosiewicz. Bolivar determined orthoptera sent by Konstanty Jelski and Jan Sztolcman from South America and by Ludwik Młokosiewicz from the Caucasus. At Taczanowski’s request, he sent to Warsaw the specimens of beetles and butterflies from Spain, the Iberian woodpecker and the African hymenoptera, determined by Oktawiusz Radoszkowski. Młokosiewicz’s letters concern specimens of insects, reptiles, birds, and mammals sent from Georgia to Madrid as well as preparations of the Bolivar expedition to the Caucasus. Letters of Polish naturalists to Bolivar are important documents of the history of the Zoological Cabinet in Warsaw and European natural history collections in the 19^th century.

The military health service of the Kingdom of Poland was organized on the basis of a specifically prepared document, namely Przepisy służby zdrowia wyięte z ogólnego urządzenia Administracyi i Rachuby wewnętrznej dla Woyska Polskiego wszelkiej broni zatwierdzonego przez Komitet Woyskowy. In its content, no aspect of activity was neglected, ranging from equipping hospitals to crucial issues of education and professional preparation of medical staff. The attempts to equate the medical staff with the officers were initiated though not completed. For the first time a permanent institution of medium medical staff was introduced. These were field surgeons, for whom also a special school was founded in Warsaw. The text elaborates these issues.

The author, inspired by Stefan Zamecki’s autobiography: Życie wśród innych [Life among Others] and the life-path of this scholar, reflects on Polish historiography of science. These deliberations are not free from personal notes and associations referring to the figures of Polish historiography of science and the hero of the analysed book. Jaromir Jeszke uses here a flexible formula of Reflections on the margins of... From the theoretical perspective of the history of science, the author finds the following fields of Stefan Zamecki’s activity particularly inspiring: 1) his attempts to introduce – and consistently use in his works – the concept of ‘science’ and its subdisciplines, e.g. ‘chemistry’; 2) organising and conducting (together with Prof. Alina Motycka, philosopher from the Institute of Philosophy and Sociology of the Polish Academy of Sciences) a nationwide seminar: ‘Context of discovery in the history of the field of science’, which was held from the mid-1990s to 2002; 3) his scientific vision of the history of science together with its organizational location among sciences on science; 4) his analytical studies on a scientific journal with a century-old tradition: Nauka Polska. Jej Potrzeby, Organizacja i Rozwój [Polish Science. Needs, Organization and Development]. Stefan Zamecki appears to the author as a critical, skeptical and aloof scholar who walked into the history of science through studies on chemistry and philosophy. This experience has shaped his theoretical, ‘boundary’, not always accepted, but inspirational attitudes.