Sidle & Poalk, Philadelphia

"The ACME" microscope No. 17, c. 1879

Sidle & Poalk, Philadelphia. The ACME microscope No. 17, c. 1879 Sidle & Poalk, Philadelphia. The ACME microscope No. 17, c. 1879



Sidle and Poalk, Philadelphia. The ACME No. 17, c. 1879

Sidle and Poalk, Philadelphia. The ACME microscope No. 17, c. 1879

Reversible on the horseshoe base

1880 advertisement

1880 advertisement

From The Journal of the Royal Microscopical Society, pg 523, 1880


sidle andPoalk microscope

Sidle and Poalk's Acme Microscope.This Microscope, shown in Fig. 39, is the first cheap instrument that we have seen with a swinging substage.

The general form of the instrument hardly needs any description, but it may be mentioned that the stage is made of two thin, circular brass plates, the upper one (shown in the lower left-hand corner) fitted to turn upon the lower, so that the object can be rotated in the field of view. The stage can bo centered. The upper plate can be removed, and two spring clips attached to the lower one, either above or below, thus making a stage for use with oblique light. The aperture in the stage has a standard-screw thread, to receive various accessories for illumination when it is desired to have the mirror move independently of them, and also to afford a means of mounting the selenite so that it can be revolved without turning the Nicol prism.

The mirror and substage are both attached by sliding fittings to the same bar, which carries them around the object as a centre. The circular piece at right angles to the stage, gives steadiness to the bar, wiith smooth movement, and is graduated to show the angular direction of the illuminating pencil.

The horseshoe base is reversible, so that greater steadiness can bo ensured when the stand is used in a horizontal position.

The Acme line of microscopes was first introduced in 1879 by the firm Sidle and Poalk of Philadelphia. The microscope shown on this web page with serial number 17 is an example of one of the first microscopes made by this firm. It was called "The Acme". By 1880, the firm was located in Lancaster Pennsylvania under the name John W. Sidle & Co. or the "Acme Optical Works". Subsequently, the entire output of the Acme factory was consigned to the retailer and manufacturer of scientific instruments, James W. Queen of Philadelphia. Later examples of microscopes from the Acme Optical Works can be found on this website. Among the various models produced were the Acme No. 3, the Acme No. 4 , and the Acme No. 5. There are some references in the literature to an Acme model No. 2, but I have not been able to locate an actual example of this microscope

Sidle Poalk microscope with case and accessories



This microscope was formerly the property of the Cascadilla Preparatory School of Ithaca New York. The school was founded in 1876 by Lucien C. Wait, a Professor of Mathematics at the nearby Cornell University. The school was established for the special instruction of students preparing to enter Cornell.



The history of the Sidle & Poalk business is summarized in the 1995 publication from the Lancaster City & County Medical Society Our Medical Heritage, chapter 15.

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