Astronomical observations made at Hudson Observatory, latitude 41° 14' 37" north, and longitude 5h. 25m. 42s. west : with some account of the building and instruments
An 1839 astronomical record by Elias Loomis, published in Philadelphia, reporting observations and the building and instruments of Hudson Observatory for a scientific readership. The single picture is an engraved isometric plan of the observatory, with a cylindrical dome and surrounding rectangular walls, drawn in fine cross-hatched lines that a designer could take as a model for architectural line diagrams.
