Span (length dimension)

Length measurements derived from the hand :
4 = (large) span
1 = small span
2, 3 = hand width
5, 6 = finger width
Further: fist

The span or hand span is a unit of length outside the International System of Units .

It is an old measure and is occasionally used as a descriptive estimate. The manageable length corresponds to about 20 cm.

definition

Depending on the location, the span was standardized differently, because the underlying hand span is individually different for each person. There are different distances to be measured on the hand, all of which are referred to as ranges. Such definitions are:

• Distance between the tip of the thumb and little finger on the open hand: large span , also called dodrans ; engl. Chip

  this corresponds roughly to: the distance between the crook of the arm and the wrist

• Distance between thumb and middle finger tip : small range

  this corresponds approximately to: the distance between the middle finger tip and the wrist

• Distance between the tip of the thumb and index finger :

  this roughly corresponds to the distance between the tip of the thumb and the hypothenar (hand's width plus thumb spread apart): in English shaftment

Dimensions and comparisons to other dimensions:

• half a cubit
• 1 dodrans = 9  inches
• in the Anglo-American system of measurement :
  • 1 span = 3 palms = 9 inches = 22.86 centimeters (exactly. According to definition 1 inch = 25.4 mm, 1956)
  • 1 Shaftment = 6 inches = 15.24 centimeters (before 1066 6½ ynches, see Old Weights and Measures (England) )
• The palmo (actually derived from the width of a hand) was a measure of length corresponding to the span in Italy and Romanic countries, but could be measured regionally on the foot
• the Väjäb in Persia is comparable to the span

Estimation of angles using the extended arm: span, fist , thumb

Uses

In astronomy , approximate distances from objects in the starry sky are given using this unit of measurement. It allows a rough estimate of the angle . The section in the sky that the span of a hand with an outstretched arm can cover corresponds to approximately 17 ° to 20 °.

Individual evidence

1. ↑ Smaller Brockhaussches Konversations-Lexikon for hand use. F. A. Brockhaus, Leipzig 1854, p. 261.
2. ↑ Oswald Thomas in Heaven and Space. , Paul Neff Verlag, Vienna / Stuttgart 1953.
3. ↑ The moon as a star and planet pointer. kuffner-sternwarte.at.