What is the missing number?
MATH PUZZLE: Can you replace the question mark with a number?Correct answers: 49
The first user who solved this task is Djordje Timotijevic.
#brainteasers #math #riddles
Envelope machine patentIn 1849, the first U.S. patent for an envelope-making machine was issued to Jesse K. Park and Cornelius S. Watson of New York City (No. 6055). It was never used commercially, as it was shortly superceded by patents on improved machines by other inventors. It was treadle-operated and its mechanism included a stamper rod, gumming apparatus and folding apparatus. The patent model still exists in the collection of the National Postal Museum.« |