This is an example of a 1924 advertisement for the Neurocalometer from the Palmer School of Chiropractic. The device is notable because it featured one of the first leasing business models in the medical equipment industry. Chiropractors didn’t purchase the device, the leased it from the company to use with patients. It allowed smaller businesses to afford to offer the service, but it also tied them to the company. This business model is in use today with many types of diagnostic and surgical equipment.