Have you seen these bird feet markings on bricks? Here’s what they really are.

You’ve probably seen these markings while you’re strolling in the city or in a park.

At first glance, you can be forgiven if you thought these were markings were made by birds on wet bricks.

Folks who enjoy history theorize that these markings are probably associated with the Britain’s Ministry of Defence since the symbol, dubbed the ‘Broad Arrow’, is traditionally used in England as a symbol of heraldry often seen in coat of arms and armor.

Turns out, these markings were neither made by birds nor soldiers. In fact these markings have a name and serve a practical purpose.

They’re called ‘benchmarkings’.

And they help land surveyors tremendously. IMAGE: SAYS.

These chiseled marks are made by surveyors and they’re typically found on stone structures.

Stony surfaces are often marked in such fashion to indicate the location an angle-iron could be placed to form a “bench” which then can be used to measure the elevation of various objects.

These fixed point of references give these markings the name, ‘benchmarks’ because they’re essentially the benchmark for surveyors to refer to when it comes to measuring elevation.

A benchmark is often used as a starting point for levelling work. Dating back to the olden days, these markings have been used to great effect, however there are many types.

G.T.S. (Great Trigonometrical Survey) benchmark.

A G.T.S. in Nagpur, India. IMAGE: We Civil Engineers.

This type of fixed benchmarks are often established by national agencies and they’re established with the highest precision based on their position and elevation above the Mean Sea Level (MSL).

Permanent Benchmark.

IMAGE: We Civil Engineers.

These types are established with reference to the GTS benchmark and are often fixed points of reference for surveyors.

Arbitrary Benchmark.

You’ll notice there are no visuals for this type because these benchmarks are often randomly assumed.

Temporary Benchmark.

IMAGE: Research Gate.

These benchmarks are pretty self explanatory. They’re created by surveyors to mark the point where a survey in the field has been completed. This way, it’ll be easy for them to continue surveying the land or identifying a spot in the event the surveyed field is large.

Now that you know what these markings are for, the next time you come across them, feel free to show off your new found knowledge to your friends or even a potential crush/date.

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Cover image sourced from Reddit.