Conservation of Deteriorating Vertebrate Paleontology Nitrate Negatives

洛杉矶县自然历史博物馆（LACM）的麦克劳德博士获得了一笔赠款，用于保存加利福尼亚理工学院（CIT）人员在1925年至1949年期间为记录收集脊椎动物化石（包括恐龙）而拍摄的变质的硝酸盐底片。虽然当时的摄影标准，但众所周知，硝酸盐底片会变质，并构成有害物质。这些硝酸盐底片代表了最好的，有时是唯一的，关于CIT化石脊椎动物收藏地点的文件，由LACM于1957年获得，另外记录了20世纪初美国西部一些地区的情况，这些地区后来由于自然原因或人类活动而发生了很大的变化。这些硝酸盐底片目前的状况从明显的原始状态到几乎完全破坏。最终，它们都会退化到无法使用的状态。根据国家公园管理局关于保存硝酸盐底片的指导方针，在国家科学基金会为该项目提供的资金支持下，将为2043张CIT现场照片制作新的交互底片、复制底片和印刷品。这将保存摄影图像，否则将失去由于变质的硝酸盐底片。博物馆将聘请一名兼职的策展助理，负责扫描硝酸盐底片上的照片，输入说明，调整图像，并将其放在博物馆的网站上，从而为外行和专业观众提供广泛的访问这些图像的途径。将聘请并培训一名兼职学生助理，以确定CIT硝酸盐负像所代表的化石地点的纬度和经度，从而为遗址的位置提供新的永久标准参考。该项目更广泛的科学意义在于，这些照片记录了北美西部大量重要脊椎动物化石的所在地。这些照片中记录的一些地区，由于自这些照片拍摄以来半个多世纪的发展，已经不存在了。教授学生如何使用现代科技来确定照片中化石遗址的确切位置，将扩大博物馆的教育活动，并加强博物馆对教育的承诺。提供对这些图像的网络访问将为广大的国际观众提供一个了解这些早期经典脊椎动物化石遗址和从中获得的收藏的门户。

A grant has been awarded to Dr. McLeod at the Natural History Museum of Los Angeles County (LACM) for conservation of deteriorating nitrate negatives of photos taken by the personnel of the California Institute of Technology (CIT) to document collecting of vertebrate fossils, including dinosaurs, during the period 1925-1949. Although standard for photography at that time, nitrate negatives are known to deteriorate and they constitute hazardous materials. These nitrate negatives represent the best, and sometimes the only, documentation of the localities for the CIT fossil vertebrate collections, acquired by the LACM in 1957, and additionally document the conditions in some areas of the western United States during the early 20th century that have subsequently been highly altered due to natural causes or human activities. These nitrate negatives currently range in condition from apparently pristine to almost completely destroyed. Ultimately, they will all deteriorate to an unusable state.Following the National Park Service guidelines for conservation of nitrate negatives, with funding from the National Science Foundation for this project new interpositives, copy negatives, and prints will be made for the 2,043 CIT field photographs. This will preserve the photographic images that otherwise would be lost due to the deterioration of the nitrate negatives. A half-time curatorial assistant will be hired to scan the photographs from the nitrate negatives, type in the descriptions, adjust the images, and place them on the Museum's web site, thereby providing wide access to these images for both lay and professional audiences. A half-time student assistant will be hired and trained to determine the latitude and longitude of the fossil localities represented by the CIT nitrate negative images, thereby providing a new permanent standard reference for the location of the sites.The broader scientific significance of the project is that these photographs document the localities for a substantial and important collection of vertebrate fossils from western North America. Some of the areas documented by these photographs no longer exist due to development in the more than half century since the collections were made. Teaching students how to use modern technology to determine the exact location of the fossil sites represented in the photographs will expand the educational activities of the Museum and enhance the Museum's commitment to education. Providing web access to the images will give a broad and international audience a portal to these early classic fossil vertebrate sites and the collections derived from them.