Astronomical Unit
An astronomical unit (AU) is a unit of distance used in astronomy to describe the average distance between the Earth and the Sun. It equals about 149.6 million kilometers (or about 93 million miles). The AU is useful for measuring distances within our solar system, such as the distance from Earth to other planets. For example, Mars is about 1.5 AU from the Sun. Using the AU makes it easier to understand and compare distances between planets without dealing with very large numbers. The symbol for astronomical unit is "AU".
Nail (Cloth)
A nail is a traditional unit of length used in cloth measurement, equal to 2ΒΌ inches or approximately 5.715 centimeters. It was commonly used by tailors and fabric merchants in England to measure small lengths of fabric.
The term βnailβ likely originates from the practice of marking lengths on a measuring stick with notches or nails, making it easy to measure fabric quickly. The nail was a convenient subdivision of the yard, with 1 yard = 16 nails.
Though obsolete today, the nail remains an interesting part of historical textile measurement systems.
Summary:
1 nail = 2ΒΌ inches (5.715 cm)
1 yard = 16 nails
Used historically in tailoring and fabric trade
Originates from notches or nails on measuring sticks
No conversions available for length.