Ah, the versatile Jacob staff. At first glance, it appears to be a simple staff, but from a historical point of view the Jacob staff has been a handy tool for surveying and navigation. It’s actually kind of a little wonder of trigonometry, which is one of our favorite subjects here at Warren Knight.
Early versions of the Jacob staff were believed to have been invented or developed by Jewish mathematician Levi ben Gerson, also known as Gersonides, in the 13th Century. Not only is Gersonides credited with developing the Jacob staff, he also developed an early version of the camera. At any rate, he was the first person in the west to describe such a device.
However, it’s also possible a similar cross-staff was used as early as 400 BC by a group of people known as the Chaldeans. The Chaldeans were an ancient people that lived in the region of Mesopotamia, and relatively little is known about them. Chinese surveyors also were thought to use some type of cross-staff as far back as the early 11th Century.
At any rate, the Jacob staff, way back then, was not just a simple pole, it featured the main staff or rod, which included a scale and then one or more cross pieces was attached to this main pole. This tool then could be used to measure angles as well as calculating heights and distances. This device could be used for surveying tasks, astronomical studies and, eventually, it even was used for navigation.
Today, Jacob staffs are used for a wide variety of tasks. For instance, a forester might use a Jacob staff with a foresters compass for a timber cruise, which is basically a survey of a forest where data is collected to determine the amount of timber, type of timber and the market value of timber.
A geologist might use a Jacob staff to measure dipping beds, and this lightweight device is easy to carry out into the field, which makes it ideal if your exposures are particularly steep. Surveyors also still might use this instrument for basic surveying tasks. You can attach a surveyor’s compass or perhaps a graphometer or Abney level and head out into the field.
Our WK-19-1400 Jacob staff measures 54 inches in height and weighs less than four pounds. Crafted from quality maple wood, you can use this staff with our foresters compass, surveyor’s compass or any other compass or instruments designed for mono pole operation.
Of course, in some cases, you might prefer to use a tripod instead of our Jacob staff. We have sturdy, high-quality tripods for just about any situation. If you need a tripod that won’t shrink or swell with changes in moisture, our WK-19-7358 Non-Magnetic Composite Tripod might be a perfect fit. This tripod can handle a work load of up to 50 pounds.
We also have several wood tripods, including an extension leg wood tripod and our wide-frame wood tripod, which provides an extra level of stability and also won’t shrink or swell under changing weather or temperature conditions. If you need an elevation tripod, we have that option available, as well.
To learn more about our tripods, head to the Stands & Tripods section under the Products tab. Our Jacob staff is located under Products, as well, but in the Navigation section. This section also contains information about our compasses, sextants and other navigational instruments. If you don’t see precisely what you need, give us a call as we may be able to provide you with a custom instrument that suits your unique needs.