In order to maintain their body temperatures, Chickadees must take in a large number of food calories which will be metabolized for body heat. Calder (1974) notes that Black-capped Chickadees ... must eat continuously during short daylight hours to stoke their metabolic fires.
Industrial sewing machines are the best option for sewing upholstery-grade fabrics such as vinyl and leather because these machines are designed to handle thicker fabrics. Industrial machines use heavier upholstery thread and often sturdier needles which penetrate the material cleanly.
Rotating abrasive wheel on a bench grinder. Pedal-powered grinding machine, Russia, 1902. A grinding machine, often shortened to grinder, is any of various power tools or machine tools used for grinding, which is a type of machining using an abrasive wheel as the cutting tool. Each grain of abrasive on the wheel's surface cuts a small chip from the workpiece via shear deformation.