were invented by the British and developed by the US and initially used against aircraft in World War II. Their ground use was delayed for fear of the enemy recovering 'blinds' (artillery shells which failed to detonate) and copying the fuze. The first proximity fuzes were designed to detonate about above the ground. These air-bursts are much more lethal against personnel than ground bursts because they deliver a greater proportion of useful fragments and deliver them into terrain where a prone soldier would be protected from ground bursts. However, proximity fuzes can suffer premature detonation because of the moisture in heavy rain clouds. This led to 'Controlled Variable Time' (CVT) after World War II. These fuzes have a mechanical timer that switched on the radar about 5 seconds before expected impact, they also detonated on impact. The proximity fuze emerged on the battlefields of Europe in late December 1944. They have become known as the U.S. Artillery's "Christmas present", and were much appreciated when they arrived during the Battle of the Bulge. They were also used to great effect in anti-aircraft projectiles in the Pacific against kamikaze as well as in Britain against V-1 flying bombs. Electronic multi-function fuzes started to appear around 1980. Using solid-state electronics they were relatively cheap and reliable, and became the standard fitted fuze in operational ammunition stocks in some western armies. The early versions were often limited to proximity airburst, albeit with height of burst options, and impact. Some offered a go/no-go functional test through the fuze setter. Later versions introduced induction fuze setting and testing instead of physically placing a fuze setter on the fuze. The latest, such as Junghan's DM84U provide options giving, superquick, delay, a choice of proximity heights of burst, time and a choice of foliage penetration depths. A new type of artillery fuze will appear soon. In addition to other functions these offer some course correction capability, not full precision but sufficient to significantly reduce the dispersion of the shells on the ground. Projectiles The projectile is the munition or "bullet" fired downrange. This may be an explosive device. Projectiles have traditionally been classified as "shot" or "shell", the former being solid and the latter having some form of "payload". Shells can be divided into three configurations: bursting, base ejection or nose ejection. The latter is sometimes called the shrapnel configuration. The most modern is base ejection, which was