Eleni alexandria biography of nancy johnson
The couple adopted two children, Walter W. Johnson and Mary Maria Stroud She started as a housewife, and later went on to be a very successful inventor, which was very uncommon in her days.
How did ellen johnson sirleaf change the world
Women were not allowed to control their own finances, own property, or sign legal agreements. This was all done by the men. Men were looked at to represent their wives, mothers, and daughters. Johnson lived in Philadelphia in when she filed for her patent for the first hand-cranked ice cream churn USA. She died in Washington, D. Ice cream was originally made using very intensive labor and it often took one individual hours to make.
Johnson had invented the hand cranked ice cream churn as a way to make ice cream faster and easier than by hand. It was patented on September 9, , and antedated on July 29, The Artificial Freezer contained a hand crank, which, when cranked, would spin and rotate two adjacent broad, flat slates containing an array of holes, which would assist in churning the ice cream, making the ice cream more uniform, while also making it easier to remove the ice crystals in the interior walls of the cylindrical container in which the spatulas were fit in.
The wooden tub contained a mixture of salt and crushed ice, thus melting the crushed ice, but dropping the temperature of the solution below freezing point as a result of salt lowering the melting point of liquids. This, in conjunction with the ice cream solution, extracts heat energy from the ice cream, in turn freezing it. Johnson also was able to create the Artificial Freezer so that when using a border to split the machine down the middle, two different flavors of ice cream could be cranked and made at the same time.
In the "artificial freezer", which was the name of the original patent, it was possible to make either ice cream or sorbet, that would last about 30 minutes.