<Li> Greek Fire: Originally an incendiary weapon perfected from the Greeks in 7th century AD, the Greek fire "is one of the very few contrivances whose gruesome effectiveness was noted by" many sources . Roman innovators made this already lethal weapon even more deadly . Its nature is often described as a "precursor to napalm". Military strategists often put the weapon to good use during naval battles, and the ingredients to its construction "remained a closely guarded military secret". Despite this, the devastation caused by Greek fire in combat is indisputable . </Li> <Ul> <Li> Testudo: This strategic military maneuver is originally Roman . The tactic was implemented by having units raise their shields in order to protect themselves from enemy projectiles raining down on them . The strategy only worked if each member of the tested protected his comrade . Commonly used during siege battles, the "sheer discipline and synchronization required to form a Testudo" was a testament to the abilities of legionnaires . Testudo, meaning tortoise in Latin, "was not the norm, but rather adopted in specific situations to deal with particular threats on the battlefield". The Greek phalanx and other Roman formations were a source of inspiration for this maneouver . </Li> </Ul> <Li> Testudo: This strategic military maneuver is originally Roman . The tactic was implemented by having units raise their shields in order to protect themselves from enemy projectiles raining down on them . The strategy only worked if each member of the tested protected his comrade . Commonly used during siege battles, the "sheer discipline and synchronization required to form a Testudo" was a testament to the abilities of legionnaires . Testudo, meaning tortoise in Latin, "was not the norm, but rather adopted in specific situations to deal with particular threats on the battlefield". The Greek phalanx and other Roman formations were a source of inspiration for this maneouver . </Li> <Ul> <Li> Pontoon Bridge: Mobility, for a military force, was an essential key to success . Although this was not a Roman invention, as there were instances of "ancient Chinese and Persians making use of the floating mechanism", Roman generals used the innovation to great effect in campaigns . Furthermore, engineers perfected the speed at which these bridges were constructed . Leaders surprised enemy units to great effect by speedily crossing otherwise treacherous bodies of water . Lightweight crafts were "organized and tied together with the aid of planks, nails and cables". Rafts were more commonly used instead of building new makeshift bridges, enabling quick construction and deconstruction . The expedient and valuable innovation of the pontoon bridge also accredited its success to the excellent abilities of Roman Engineers . </Li> <Li> Pilum (spear): The Roman heavy spear was a weapon favored by legionaries and weighed approximated five pounds . The innovated javelin was designed to be used only once and was destroyed upon initial use . This ability prevented the enemy from reusing spears . All soldiers carried two versions of this weapon (a primary spear and a backup). A solid block of wood in the middle of the weapon enabled legionaries protection for their hands while carrying the device . According to Polybius, historians have records of "how the Romans threw their spears and then charged with swords". This tactic seemed to be common practice among Roman infantry . </Li> </Ul>

What were roman accomplishments in math and science