A Biblical specification and a problem solved (almost)

We are justifiably proud in England of the legal principles laid down in Magna Carta in 1215, but less supportive of its command, “Let there be one measure …”. However, weights and measures laws are as old as civilisation. In this article, Ronnie Cohen looks at a unit of length from 3000 years ago, and makes a comparison with today.

Every week, the Jews read a portion of the Pentateuch in their sabbath morning services in the synagogue in an annual cycle of readings. On Saturday 21 February 2015, they read the portion about the construction of the Tabernacle. This portion can be found in chapters 25 to 27 in the book of Exodus, which describes the construction in great detail and involves a large number of measurements. The unit of length used throughout this section is the cubit.

The objects involved in constructing the Tabernacle included:

  • 1 Altar
  • 1 Ark
  • 1 Cover
  • 1 Table
  • 21 Curtains
  • 48 Planks of Wood

The dimensions in cubits used for the objects of the Tabernacle are shown in the following table:

Object Length Width Height
Ark of Acacia Wood
Cover of Pure Gold N/A
Table of Acacia Wood 2 1
Curtains for the Tabernacle 28 4 N/A
Curtains for the Tent over the Tabernacle 30 4 N/A
Planks of Wood for the Tabernacle 10 N/A
Altar of Acacia Wood 5 5 3

The curtains for the tent were slightly longer than the ones for the Tabernacle. The text specifies that the overhang of the tent curtains over the Tabernacle should be one cubit on each side. There are some other measurements for the lace-hangings of the Courtyard on all sides, as described in the following list:

  • North Side: 100 cubits long with 1 pillar at each 5-cubit interval.
  • South Side: 100 cubits long with 1 pillar at each 5-cubit interval.
  • West Side: 50 cubits long with 1 pillar at each 5-cubit interval.
  • East Side: 50 cubits long. This section was subdivided into Shoulder 1 (15 cubits), Shoulder 2 (15 cubits) and the Screen (20 cubits). For all of these sections, there was 1 pillar at each 5-cubit interval.

This account was written about events that took place around 3000 years ago. It describes the requirements of a portable dwelling place for the divine presence to accompany the Israelites in the period between the exodus from Egypt and the conquest of Canaan, and it reminds us of the importance attached then to a standard measure for length and to consistency in the use of measures in construction.

So what was the length of a cubit?

It was based on the distance from the elbow to the fingertip, so it varied between different peoples and cultures, as this table shows:

Culture                              cubit (mm)

Hebrew                              445 (short cubit)
Egyptian                            447 (short cubit)
Ancient Greek                  462
Babylonian                        503 (long cubit)
Sumerian                           519
Egyptian                            523 (long cubit)

Thus, the ancient world foreshadowed a problem that would appear in Europe following the collapse of the Roman Empire, namely the absence of consistent measures. By the middle of the eighteenth century, there were, for example, many different versions of the mile, the foot and the pound. This was a cause of considerable frustration to scientists like James Watt as they tried to compare their experimental results with those from elsewhere in Europe. The problem was solved, as we know, by the universal adoption of the metric system in the nineteenth and early twentieth century.

Not quite universal, unfortunately. The UK still uses a mixture of ancient and modern, feet and metres, for length (and height), and is the only country in Europe that has not adopted metric measures for its road traffic signs. But whereas the different cultures of the ancient world had practical reasons for inconsistency, the same can not be said of us.

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2 Responses to A Biblical specification and a problem solved (almost)

  1. Martin Vlietstra says:

    It would appear that Noah's team all used the same cubit, the evidence being that the Ark floated. This was not the case in Johannesburg.

    During the gold rush of the 1880's the heart of the new city was laid out in a hurry. Plans were drawn up to lay the city out in a grid and two surveyors got the contract for the work. Both used the same plans with one surveyor taking the northern part of the city and the other the southern part. Unfortunately the surveyor who measured the southern part was unaware that the Cape foot, not the English foot was the unit of measure used by surveyors. There are 1.033 English feet in one Cape foot. The result was a kink in the North-South roads as they crossed Bree Street. As one moved eastwards along Bree Street, the kink became larger.

    The Cape foot continued to be the surveyor's unit of measure in three of the four South African provinces until metrication in the 1970's. Only Natal used the English foot. Between 1919 and 1990, South West Africa (now Namibia) was effectively a fifth province of South Africa. Having been a German colony South West Africa's surveyors had always used metres, not feet.

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  2. John Frewen-Lord says:

    I postulated in 2013 in an article in MV (http://metricviews.org.uk/2013/06/was-the-metre-invented-by-the-ancient-egyptians-4500-years-ago/) that the Egyptian Royal Cubit (example on display in the Liverpool Museum) may have been derived from the metre. In particular, the cubit's length of 0.5236 m is to be found in some mathematical phenomena involving pi and Phi and their relationship to the metre.

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