This small portable device is one of the classic models in the history of microscopes. Its mahogany case lined with blue velvet, only measures 9.5 x 7.5 x 3.5 cm. This Cary-Gould pocket microscope houses its nine component parts. Its stand is the box itself, fixing the support shaft, by means of a thread in its front part. The support shaft has a toothed chain on its rear that the stage rides on to facilitate focusing. This has a circular space to house a circular brass device, with glass in the center to observe live insects. Under the stage there is a space formed with another metal plate with the same hole that allows the preparations to pass for observation.
The microscope has three circular lenses of different magnifications that are screwed in successively, achieving a greater number of magnifications. Over these you can screw a conical shaped optical tube that has one lens in its eyepiece and another inside. The third lens is painted black and is the one with the highest magnification, being used alone for observation. With this set of lenses, 6,400 increases are achieved.
This model is considered to have been designed by Charles Gould, a Cary employee, and who described it in the book: “The companion of the microscope and the Gould’s improved pocket Microscope “.London: soldby Cary at 181 Strand. This first edition was made in 1826. In 1835 the tenth edition was printed with some changes in its content. On June 10, 1826, an entry is reflected in The London Mechanics ’Register announced“ Mr. C. Gould’s Patent Portable Compound Microscope ”. This record occurs shortly after the death of William Cary. This suggests that Gould, although employed by the Cary firm, had a great deal of autonomy.
Shortly after its description and registration, this model was imitated by numerous manufacturers. In order to guarantee the authenticity of the originals, they were sold together with the Gould-Cary book describing the microscope and some test preparations to demonstrate the quality of their images. Also to guarantee its authenticity a third lens of higher magnification of black color was described, with a small hole that accompanied the apparatus.