(1) Although Philadelphians were intrigued by the invention of the daguerreotype , photographic portraits did not fully meet their needs during the 1840s and 1850s.(2) In the mid 19th century, Scottish photographers were among the first to use the variety of photographically linked techniques such as the calotype, daguerreotype and photogravure.(3) Talbot's negative-positive process was a major factor in the decline of the daguerreotype - which was a one-shot, like a Polaroid.(4) After all, it is no coincidence that the daguerreotype in its highly polished and silver plated form was known as the ├ö├ç├┐mirror with the memory.├ö├ç├û(5) In the mid-1800s, with the invention of the daguerreotype and the fixed printing processes of William Henry Fox Talbot, photography as a tool of art and science rapidly evolved.(6) Over the summer I had established that my photograph in fact was a copy of a daguerreotype made years earlier.(7) Within a few months of the announcement of the first daguerreotype in Paris in 1839, photography had arrived in India.(8) Like all the archaic photograph processes - and like a Polaroid - the daguerreotype delivers instant gratification.(9) In the French version of this exhibition, for example, a daguerreotype titled Study of Rocks appeared in a section titled ├ö├ç├┐Vues de Paris et de France.├ö├ç├û(10) Its inventor around 1820 was the French landscape painter Louis Daguerre, later a pioneer of photography and originator of the daguerreotype .(11) Starting with the invention of the daguerreotype in France in the late 1830s, photography has undergone a succession of technical innovations.(12) Like the earlier daguerreotype , each image is unique, made one at a time in the camera.(13) Studio photographers produced most of the earliest images using standard-sized plates for daguerreotypes , ambrotypes, and tintypes.(14) In the first three chapters of her book, Sandweiss focuses on early daguerreotypes taken by photographers during the Mexican-American War and by photographers employed to document early government expeditions to the West.(15) Most of the earliest daguerreotypes were portraits.(16) Those who mastered the rather complicated process of making daguerreotypes were awestruck that these pictures revealed details invisible to the naked eye.