Glass lenses, for use as magnifiers or for starting fires, date to about 300 BC, but the first eyeglasses to aid or correct vision were almost certainly invented in 1280 in Florence, Italy by the Dominican friar Alessandro della Spina and / or his friend, the physicist Salvino degli Armati. Prescribed for far-sightedness, the glasses had convex lenses and were worn by Armati, who had injured his eyes while performing light refraction experiments and discovered that it was possible to enlarge the appearance of objects by looking through two pieces of convex glass.It was in the early fourteenth century that concave lenses were used to correct near-sightedness. In fact, Pope Leo X was depicted wearing glasses, with concave lenses, in a 1517 painting by Raphael. Whereas early eyeglasses were made of polished quartz, by the sixteenth century developments in glassmaking made it possible to mass produce them from glass. Bifocals, the combination of both concave and convex lenses for both types of vision correction, a top lens for distant viewing and a lower lens for reading, were developed around 1760 by the American statesman and inventor Benjamin Franklin.
In no year.
Benjamin Franklin did not invent bifocals; they had been invented by two other people, independently of each other, many years before.
Benjamin Franklin invented bifocals in 1784!!
Ben Franklin invented bifocals in August of 1784. He was quite pleased to finally have spectacles that allowed him to see things close up as well as at a distance.
1258 with help from Salvino D Armate ,they did this in Italy.
1784.
The exact date of when Benjamin Franklin invented the Swim Fins is unknown.
1727?
Benjamin Franklin performed his famed kite experiment some time in June of 1752. Many historians don't agree with an exact date since there is only Franklin's account of the event, but the exact date is thought to have been June 10th.
Febuary 30th 1713......B.C.
If Ben Franklin was up-to-date with modern day civilization he wouldn't have a problem. The Bible was created to explain natural happenings just like Greek mythology. Science proved that we didn't need a god. Ben Franklin was smart enough to understand that.
The exact date of when Benjamin Franklin invented the Swim Fins is unknown.
Benjamin Franklin was born on January 17, 1706.
April 17, 1790.
As far as it is known to the date, Benjamin Franklin did not work with other scientists. Even if he is famous for having worked in many areas of knowledge (from electricity to politics), Benjamin Franklin is believed to have done everything on his own.
1727?
The French and Indian war prompted Benjamin Franklin to use a political cartoon to stress the need for Colonial unity .
Benjamin Franklin performed his famed kite experiment some time in June of 1752. Many historians don't agree with an exact date since there is only Franklin's account of the event, but the exact date is thought to have been June 10th.
Benjamin Franklin was born in Milk Street, Boston, Massachusetts, on January 17th, 1706, according to the Gregorian calendar. Sometimes, the date is given as January 6th, 1705, the contemporary date by the then-used Julian calendar.
Febuary 30th 1713......B.C.
Benjamin Franklin's portrait is still on the $100 bill, regardless of series date.
1949 is not a hard date to come by for Franklin half dollars, actually all Franklin halves regardless of mintmark are common and most circulated coins are valued for the silver only, about $15.00. The retail values for this date run from $17.00 to $22.00 depending on the actual grade of the coin.
1980 see the link below. See the link for your date of manufacture