Other viruses that can cause colds include coronavirus, respiratory syncytial virus, influenza and parainfluenza. Colds cause a lot of people to stay home. The CDC says 22 million school days are lost each year in the U.S. because of them. Some estimates say that Americans have 1 billion colds a year. For more detail, see Common Cold Causes. How a Common Cold Starts. You can catch it from another person who is infected with the virus. This can happen by direct physical contact with someone who has a cold, or by touching a surface contaminated with their germs -- like a computer keyboard, doorknob or spoon --- and then touching your nose or mouth.
The hypocaust system. The hypocaust system (hypocaustum in Latin) was a heating system used in (wealthy) Roman homes and Roman baths, and the closest thing to central heating today. The hypocaust was a system that circulated hot air under the floor and surrounding walls. Hypocaust construction
But what DID they use for toilet paper? Well, you could use a leaf, a handful of moss or your left hand! But what most Romans used was something called a spongia, a sea-sponge on a long stick. The stick was long because of the design of Roman toilets. Public facilities had a long marble bench with holes on top â for the obvious thing â and holes at the front: for the sponge-sticks. There were no doors or dividing walls. You sat right next to your friend and did what you had to do. Most Romans wore tunics (a garment like a long tee-shirt) and probably nothing underneath. So you could just hike it up in back and sit on the cool marble seat, leaving the front of the tunic to cover your knees and your modesty.