The technologies for displaying the wonders of the heavens to earthbound audiences have changed over the years.

Around 1900, the technology of choice for astronomy lectures was the lantern slide. In 1895, the Royal Astronomical Society, which is celebrating its bicentenary this year, started to issue a series of high-quality lantern slides of astronomical subjects.

Two of the slides highlighted the image-capturing capabilities of the Dominion Astrophysical Observatory’s 72-inch reflector in Saanich, British Columbia. The astrophotographer was the observatory’s first director, J.S. Plaskett (1865-1941), who was also the first Canadian astrophysicist of world repute. Plaskett’s image of M13, the great globular cluster in Hercules, stands up fairly well today.

For more on Plaskett and the early history of the Dominion Astrophysical Observatory, see Peter Broughton’s recent biography, Northern Star.

Through Time’s Lens is published in every edition of SkyNews.