A pair of strew slides from the HMS Challenger expedition, 3rd March 1874 (slides 22 and 22a). Prepared by Bernard Hartley. Location 53°55’S, 108°35’E (Indian Ocean, between Australia and Antarctica as shown by the screen shot from https://www.gps-coordinates.net/). It says ‘per I.T. Buchanan’ but I am wondering if this should be J.Y. Buchanan as he was the chemist on the HMS Challenger. Mounted in Arocolor and dated April 1975.
Olympus BHB microscope using 450nm LED light. 10x Nikon Plan Apo NA 0.65 objective. Olympus Aplanat Achromat condenser, brightfield lighting. 2.5x Nikon CF PL photoeyepiece. Monochrome converted Nikon d850 camera. Single unstacked images. The slides are quite dense with material which makes imaging individual diatoms ‘challenging’ (sorry). Nice range of species including a small number of Asteromphalus sp.
More on the HMS Challenger expedition can be seen at the Royal Museum Greenwich website here.