deepstash
Beta
Frank Morgan
@frankiem
Nathan Ames, an inventor, applied for the patent in 1859 for the first kind of moving stairs, with a belt attached with three wheels, and powered by kinetic energy. This was never built.
As the 19th century came to an end, there were improvements in the way people lived and worked, facilitating the development of malls, skyscrapers, and electric subway trains. The print and photography industry paved the way for better advertising of products and services.
57 SAVES
329 READS
IDEA EXTRACTED FROM:
TOPICS IN THIS IDEA
RELATED ARTICLES & IDEAS
Autumn M.
@autumn_mm95
Fountain pens, although stylish, were messy and impractical.
In 1945, Gimbels started to sell a new kind of ink pen, made by the Reynolds International Pen Company. With its quick-dry ink a...
The first generation of ballpoint pens cost around 55 shillings (£82.50/$107.50 in 2020 prices). It was in the same style as fountain pens. They were made of metal and intended to be refilled with ink. But with so many companies selling it, the market became saturated, buying refills, but not more pens.
Italian-born French industrialist Michel Bich added the catalyst of disposability. He understood the concept of the mass market and created his new company, Societe Bic. His pen only cost a shilling.
The ballpoint pen was the equivalent of today's smartphone. Before the ballpoint pen, writing was a stationary act that had to be done on a certain kind of desk, with all the other things at hand that allowed you to write.
The ballpoint pen turned writing into something that could happen anywhere. Plastic mass production allowed the pens to become even cheaper, allowing for the transformation of societies.
Planes can fly quite easily without engines, as gliders (planes without engines), paper planes, and gliding birds show us.
A plane's engine is designed to move the plane for...
A plane throws the air down behind it by making a spinning vortex - a kind of mini-tornado.
Most of the vortex is moving downward, but not all. There's a huge draft of air moving down in the center, but the air also swirls upward on either side of the wingtips, reducing lift.
If you're in a plane and steering around a circle, the centripetal force comes from leaning into a curve, just like a cyclist leans into a bend.
Steering involves banking, where the plane tilts to one side causing the one wing to dip. The plane's overall lift is tilted at an angle, making some of the lift act sideways. This sideways part of the lift provides the centripetal force that makes the plane go around in a circle. But turning the plane in a circle will make it lose lift and altitude, unless the pilot uses the elevators to increase the angle of attack to cause lift again.
Deepstash is better on the app. Discover new ideas and get inspired daily.