Here is a collection of his snowflake photographs from 1890...
According to The Smithsonian, Bentley photographed more than 5,000 snowflakes during his lifetime.
In 1925, he told The American Magazine that his work had led him to the belief that all snowflakes are unique.
Before his death (from the pneumonia he caught whilst walking in a blizzard), Bentley reflected on his love of snow, writing, "The farm folks, up in this north country, dread the winter; but I was supremely happy, from the day of the first snowfall."
Under the microscope, I found that snowflakes were miracles of beauty; and it seemed a shame that this beauty should not be seen and appreciated by others. Every crystal was a masterpiece of design and no one design was ever repeated. When a snowflake melted, that design was forever lost. Just that much beauty was gone, without leaving any record behind.