1.   The TRACE model uses activation and inhibition to suppress certain words.

2.   A number have several codes because some models use one remote-control system while others use another.

3.   Computer models use similar mathematical techniques to describe the atmosphere, methods that sometimes result in similarly wrong forecasts.

4.   Each model uses a different cradle, so a user who upgrades has to buy new accessories.

5.   Earlier models used support arms to hold the receiver over the middle of the dish, but the arms blocked some of the incoming radio waves.

6.   Evaporative models use a fan to pull air through a water-soaked filter.

7.   Future models will use radar to cut the engine when an obstacle is detected, he says.

8.   His models used hand mallets to chip away at dresses made of sugar glass which cracked when they moved.

9.   Later models used magnetic tape.

10.   Like all electronic devices, these will have to be checked and maintained, but the newest models use a five-year battery.