Halberd forms of the voulge in design and usage. The halberd was usually 1.5 to 1.8 metres (5 to 6 feet) long. The word has also been used to describe a weapon of the Early Bronze Age in Western Europe. This consisted of a blade mounted on a pole at a right angle. A very similar weapon, the dagger-axe, from Bronze Age China, has also been called "halberd" in English. The halberd was inexpensive to produce and very versatile in battle. As the halberd was eventually refined, its point was more fully developed to allow it to better deal with spears
Types of volcanic eruptions propels it forward. Phreatomagmatic eruptions are another type of volcanic eruption, driven by the compression of gas within magma, the direct opposite of the process powering magmatic activity. The third eruptive type is the phreatic eruption, which is driven by the superheating of steam via contact with magma; these eruptive types often exhibit no magmatic release, instead causing the granulation of existing rock. Within these wide-defining eruptive types are several subtypes. The weakest are Hawaiian and submarine, then Strombolian, followed by Vulcanian and Surtseyan. The stronger eruptive types are Pelean eruptions, followed by Plinian eruptions; the strongest eruptions are called