Iowa State Historical Museum, Part 3

One of the things I discovered at the museum that fascinated me was a description of surveying and how the surveying chain was used. I’d seen the surveying chain Cathy’s grandfather had used, back in the late 1800s. I had seen surveying chains in exhibits in many museums and books. After all, George Washington had been a surveyor. I knew from history that, while people had been doing various types of surveying for millennia, surveying was evolving rapidly in the mid-1700s. But this was the first time I’d seen that chain defined and explained.

As they do today, surveyors in the mid-1800s used compasses and levels, but the chain was a key part of their equipment. Each chain was made up straight links, with each link being 7.92 inches in length. Twenty-five links equaled a rod. One hundred links equaled one full chain (though surveyors often carried half-chains, to cut down on weight). One full chain was 66 feet, or four rods.

Eighty chains equal one mile (5,280 feet or 320 rods). Reading that, everything else I knew about the settling of the territories fell into place. One mile was a key measurement. The Land Ordinance of 1785 divided the new territories using a grid. One square mile was a section, and 36 sections equaled one township. A township was six miles on each side. Land was sold by the section (one square mile is 640 acres), or, for those who couldn’t manage a farm that large, one-half or one-quarter section. Flying over the Midwest even today, one can still discern the mathematical precision of the initial surveys that divided the territories up into townships and sections—the grid is still there.

The thing that amazes me is not that they came up with this plan, but that people actually walked around with these chains and marked out the entire center section of the United States. It is daunting now simply to drive across the vast plains, but to tackle them on foot, to measure the land one chain at a time, and to document it so well that we still recognize those townships is really stunning. We may have cooler tools today, but we do not have more astonishing accomplishments.

Photos and more info on surveying and map-making in 1800s can be found on this website: http://www.oshermaps.org/exhibitions/american-treasures/iv-nineteenth-century-surveying

Advertisements

Leave a comment

Filed under Agriculture, Culture, Farming, History, Midwest, Thoughts, Travel

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s