List of lost inventions

• Artificial petrifaction of human cadavers invented by Girolamo Segato[1]
• Greek fire, a Byzantine incendiary weapon used to set enemy ships on fire.[1]
• Panjagan, a projectile weapon or archery technique used by the later Sasanians that could fire a volley of five arrows.

It's unknown whether these inventions truly existed, had all of their described properties, or were truly novel.

• Archimedes' heat ray, a device that Archimedes is purported to have used to burn attacking Roman ships during the Siege of Syracuse.[1]
• Roman flexible glass, whose inventor was reportedly beheaded so that gold and silver would not be devalued.[2]
• The Glass Flowers at Harvard, widely believed to be unreproducible and made by secret and now lost technique or equipment, but actually attributable to the extraordinary skill of the craftsmen.
• Iron pillar of Delhi, notable for the rust-resistant composition of the metals used in its construction
• Mithridate, said to have functioned as a panaceaic antidote.[1]
• Sloot Digital Coding System, reported to have been able to store a complete digital movie file in 8 kilobytes of data.[3]
• Stradivarius stringed instruments, considered some of the finest instruments ever made. Theories explaining their purported quality include denser wood unique to the time period due to Solar activity, treatment with other materials like calcium and aluminium which have been found in a 2016 shaving, and technique.[1] However, blind experiments have never conclusively found a difference between the sound of Stradivari's violins and other high-quality violins.
• Starlite is an intumescent material said to withstand enormous amounts of heat.[2]
• Zhang's seismoscope, also known as houfeng didong yi, an ancient Chinese seismometer. Multiple modern recreations have been created, but it's debated whether they are mechanical replicas.[4] Hong-sen Yan claims that they do not reach the seismoscope's historically reported level of accuracy and range.[5]

• Out-of-place artifact