MATH PUZZLE: Can you replace...
MATH PUZZLE: Can you replace the question mark with a number?Correct answers: 286
The first user who solved this task is Thinh Ddh.
#brainteasers #math #riddles
First glass plate photoIn 1839, John Herschel made the first (remaining) photograph on glass plate. The image he captured was of the 40-foot, 48" aperture telescope used by his father William Herschel, in Slough, England. It had sat decades without use, and was dismantled a short time later. Twenty years earlier, in 1819, Herschel published the results of his experiments with silver and salts. A chance comment about Daguerre's experiments in a letter to his wife on 22 Jan 1839 from a friend prompted John into new activity, and within a few days, he had prepared some photographs. In papers he published in 1840-42, he coined the new words "emulsion", "positive" and "negative" and reinforced Stenger's earlier introduction of the word "photography."« |