Present industrial conditions have tbrccd the engineering trades of the country to adopt methods of mass production, in order to cope with increases in the cost of raw materials and labour. Specialized trades such as the manufacture of scientific instruments are unable to develop quite on these lines, partly because of the limited demands for their goods, and partly because each job is largely an individual one. In the microscope trade much has been done by systematic shop organization, and at the same time an approach is made to mass production by considerably reducing the number of models made, and standardizing the remainder. Naturally the large models for special work have been most affected.