[Physics Class Notes] on Cubit Pdf for Exam

A Cubit Measure is an ancient measurement of length, which is approximately equal to the length of a forearm. A cubit was typically approximately 18 inches or 44 cm, though there was a long cubit of about 21 inches or 52 cm.

In simple words, a cubit meaning is, it is among the various ancient units of length based on the length of the forearm from the elbow to the tip of the middle finger and generally equivalent to around 18 inches or 46 centimetres.

Cubit Meaning

The English word “cubit” comes from the Latin noun, viz: cubitum (which means an “elbow”), from the verb Cubo, Cubare, Cubui, Cubitum that means “to lie down”, from which also comes the adjective “recumbent’.

One Cubit To Feet

One cubit is equal to 1.5 feet.

Egyptian Cubit 

Cubit is a unit of linear measurement that was used by many ancient and medieval peoples. 

It was originated in Egypt about 3000 BC; it thereafter marked its presence ubiquitous in the ancient world. 

A cubit is usually taken as equal to 18 inches or 457 mm. This unit was based on the length of the arm from the elbow to the tip of the middle finger and was considered the equivalent of six palms or two spans. In various ancient cultures, it was as long as 21 inches or 531 mm.

Cubits of various lengths were found in many parts of the world in antiquity, during the Middle Ages, and also in early modern times. The term is still used in hedge laying, where the length of the forearm being often used to determine the interval between stakes positioned within the hedge.

Royal Cubit 

The ancient Egyptian royal cubit or “meh niswt” is the earliest known standard measurement of length. 

Cubit rods were used for the length measure. A number of these rods have survived: in which two are known from the tomb of Maya, i.e., the treasurer of the 18th dynasty pharaoh Tutankhamun, in Saqqara, and another was discovered in the tomb of Kha viz: TT8 in Thebes. 

Fourteen such rods, including one double cubit rod, were taken and compared by Lepsius in 1865; these cubit rods range from 523.5 to 529.2 mm, i.e., from 20.61 to 20.83 inches in length, and were divided into seven palms, where each palm was divided into four fingers, and the fingers were further subdivided.

Biblical Cubit

The standard of the cubit was called “Hebrew: אמה‎” in different countries and varied in different ages. This realization led the rabbis of the 2nd century CE to clarify the length of their cubits, stating that the measure of the cubit of which they have spoken “applies to the cubit of middle-size”. 

 

In this case, the need is to make use of a standard 6 handbreadths to each cubit, and which handbreadth was not to be perplexed/confused with a raised or outstretched palm, but rather one that was clinched and which handbreadth has the standard width of four fingerbreadths, where each fingerbreadth being equal to the width of a thumb, about 2.25 cm. This puts the handbreadth at roughly nine centimetres (3.5 inches), and 6 handbreadths or 1 cubit at 54 centimetres, i.e., 21 inches. 

 

History of Cubit

Epiphanius of Salamis, in his treatise On Weights and Measures, describes how it was plainly, in his day, was to take the measurement of the biblical cubit: “The cubit measure is a measure, but it is taken from the measurement of the forearm”. 

 

Cubit is the part from the elbow to the wrist and the palm of the hand. The middle finger of the cubit measure being also stretched/extended at the same time and there being added below (it) the span, that is, of the hand, taken all together.

 

Rabbi Avraham Chaim Naeh put the linear measure of a cubit at 48 centimetres, i.e., 19 inches. Avrohom Yeshaya Karelitz (the “Chazon Ish”), accepted and put forth the length of a cubit at 57.6 centimetres (22.7 in).

 

Afterwards, Rabbi and philosopher “Maimonides”, following the “Talmud,” made a difference between the cubit of 6 handbreadths employed in ordinary measurements, and the cubit of 5 handbreadths employed in measuring the Golden Altar, the base of the altar of burnt offerings, the horns of the altar, and the circuit.