The instrument's main coarse focus is by push-pull sliding of the main optical tube, which has a smooth action and is very intuitive to use, also holding in position as it should. There's also a brass eyepiece draw-tube which can be extended and increases the magnification.
Fine focus is achieved via a brass thumb-wheel at the rear of the upper frame which moves the fine focus mechanism against sprung resistance and works very well with a smooth operation. Turning to the optics, this microscope comes fitted with a nice selection of period eyepieces, as follows.
2 - 6x magnification - No. 4 - 10x magnification - Beck High-Power - about 15x magnification. There is one brass objective fitted, which is 2/3rds inch and therefore about 10x magnification giving the instrument a magnification range of 60x to 150x as currently configured and this can be increased slightly by extending the eyepiece draw-tube. The rectangular brass stage has original brass clips and this system is excellent for retaining slides for viewing and display. With the sub-stage, we currently have a fixed aperture brass plug-in stop arrangement.Lighting is via a single-sided concave mirror on an adjustable gimbal mount. The mirror is in pretty good condition showing some age-related foxing but still perfectly functional. All controls operate reasonably smoothly including coarse focus, fine-focus and the concave mirror. The instrument has been cleaned and lubricated so all controls operate as intended. Overall its dimensions are: - height - just over 10 inches tall rising to over 12.5 inches when fully extended via eyepiece draw-tube as per listing photos. Width of base - 5.5 inches at widest point of tripod, 2.25 inches wide at rear.
Length of base - 5 inches. In summary, this is a charming visual and also a capable working example of a classic Henry Crouch instrument, simple in design, but well made and one which has withstood the passage of time very well. It's essentially very much in collectable condition, displaying amazingly well for a compact stand. There is also a period hardwood case with this example with brass carry-handle, internal lens racking and a latch to keep the door closed. The case does have a shrinkage crack to its rear panel, but is otherwise in pretty good period condition for its age.Thanks for looking - please also check out my other listings if you get a chance. The item "Antique Henry Crouch Compact Brass Student Microscope No. 5729, c1890s, Cased" is in sale since Wednesday, November 10, 2021. This item is in the category "Antiques\Science/Medicine\Scientific Instruments". The seller is "arcboutant" and is located in Glasgow. This item can be shipped to United Kingdom, Antigua and barbuda, Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Australia, United States, Bahrain, Canada, Japan, New Zealand, China, Israel, Hong Kong, Norway, Indonesia, Malaysia, Mexico, Singapore, South Korea, Switzerland, Taiwan, Thailand, Bangladesh, Belize, Bermuda, Bolivia, Barbados, Brunei darussalam, Cayman islands, Dominica, Ecuador, Egypt, Guernsey, Gibraltar, Guadeloupe, Grenada, French guiana, Iceland, Jersey, Jordan, Cambodia, Saint kitts and nevis, Saint lucia, Liechtenstein, Sri lanka, Macao, Monaco, Maldives, Montserrat, Martinique, Nicaragua, Oman, Pakistan, Peru, Paraguay, Reunion, Turks and caicos islands, Aruba, Saudi arabia, South africa, United arab emirates, Ukraine, Chile, Bahamas, Colombia, Costa rica, Guatemala, Honduras, Jamaica, Kuwait, Panama, Philippines, Qatar, Trinidad and tobago, Uruguay, Viet nam, Russian federation.