Vilnius Dallmeyer Photoheliograph Solar Photographs (1869–1874)

This dataset contains 283 surviving solar photographs acquired with the Vilnius Dallmeyer photoheliograph between 1869 and 1874. The instrument was among the earliest photoheliographs ever built and represents a key milestone in the development of solar photography. The photographs have been digitized at high resolution and preserved for long-term access and reuse in research on solar physics, historical astronomy, and scientific instrumentation.