The Pressure still has much to offer. Almost any food that you can cook with moist heat can be cooked in one. The four quart cooker seams to be the most versatile size.
In many cases, a pressure cooker will cook as fast as a microwave oven. Chicken and pot roast come out tender in less than an hour.
My first experience with a pressure cooker was with canning. the pot doesn't let the steam escape no matter how hot it is since it will not get above 212 degrees or how long it cooks.
Americans were introduced to the Pressure cooker in 1914 but a Frenchman, Denys Papin, made the first pressure cooker in 1679. The designed of the pressure cooker causes it to trap the steam and seal the pot with the rubber ting on the lid. The steam builds the pressure and temperature. The pressure gauge on the lid will tell you the pressure.
I was always told this could be dangerous. The safety vent is just that. The valve through which excess steam escapes and air reenters as the cooker cools and pressure drops. Do Not. Repeat Do Not let the vent get clogged this could cause an explosion. If the vent is clogged during cooling periods the air will not come in and you would be scalded when opening the pressure pot. If you use a pressure cooker read all the directions and be careful.
Nutrients are preserved with this type of cooking.
To prevent accidents learn about all the parts, how they work together. Never leave the pot unattended even for a few minutes. Don't ever open the pot immediately after removing from heat. Only open after the gauge drops to zero. Check often for cracked, stretched, or worn parts. Follow the manufacturer directions for yearly service.