Lowell National Historical Park is a National Historical Park of the United States located in Lowell, Massachusetts. Established in 1978 a few years after Lowell Heritage State Park, it is operated by the National Park Service and comprises a group of different sites in and around the city of Lowell related to the era of textile manufacturing in the city during the Industrial Revolution.
A heddle is an integral part of a loom. Each thread in the warp passes through a heddle, which is used to separate the warp threads for the passage of the weft. The typical heddle is made of cord or wire, and is suspended on a shaft of a loom. Each heddle has an eye in the center where the warp is threaded through. As there is one heddle for each thread of the warp, there can be near a thousand heddles used for fine or wide warps.
A patent application or patent may contain drawings, also called patent drawings, illustrating the invention, some of its embodiments (which are particular implementations or methods of carrying out the invention), or the prior art. The drawings may be required by the law to be in a particular form, and the requirements may vary depending on the jurisdiction.