0
Still curious? Ask our experts.
Chat with our AI personalities
Professor
Jordan
Devin
Add your answer:
Earn +20 pts
What materials were used to build the first microscope?
Telescopes and microscopes were invented around the same time, by connecting pairs of lenses made from curved circles of glass (convex and concave lenses). Opaque tubes are used to limit light coming from outside the connected lenses.
What date did Benjamin Franklin invent the bifocals?
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.
What are the differences between an ogee and a Roman ogee profile in woodworking?
An ogee profile in woodworking has an S-shaped curve, while a Roman ogee profile has a more pronounced S-shape with a concave section followed by a convex section.
What is a Roman quern?
A quern is a very basic hand mill used for grinding grain. It generally had one stone with a concave surface and the other with a convex surface. The Roman quern was larger and consisted of larger heavier stones which were rotated by animal power.
What did German create?
Mauser bolt-action rifles Bicycles Blue Jeans (Levi Strauss) Bunsen Burners Contact Lenses
