We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.
Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.
23 BRASS LENGTHENING TUBES. For Lanterns when long Focus Lenses are used, 2-in., 4/6; 4-in., 5/6; 6-in., 7/-; 8-in., 9/-. BEST SINGLE ACHROMATIC LENSES. In Brass Cells for showing pictures at long distances (6-in., 8-in., 10-in., and 12-in. focii). “New Triple-Rack Telescopic Optical Lantern Objective,” With short and long focus Double Combination Achromatic Lenses. (Patent No. 14809). For Lime Light Lanterns only. No Lengthening Tubes required. This new Patent Rack Front is made to carry short and long focus Double Com- bination Achromatic Lenses, for showing pictures at short and long distances from the screen with Bi-unial and Tri-unial Lanterns, and with single lime light Lan- terns, and pairs of lime light Lanterns, without any leng^thening tubes being required. The brass front (which is of best make and finish), has 3 Telescopic Draws, with rack and pinion adjustment to each draw, with a range of 7^ inches, being sufficient to allow 11 -inch focus Lenses to be used without any lengthening tubes. The Lenses (which are Double Combination Achromatic, with large size Lenses to the back combination), are mounted in brass Cylinders which slide into the smallest telescopic draw of the front, each Cylinder being fitted with a Sliding Shutter or Flasher, having grooves to carry shapes of coloured glass for tinting slides. The Cylinders are of the following focii, and each one has the focal length engraved on it. No. I Cylinder, 4j-inch back focus. No. 3 Cylinder, 9-inch back focus. No. 2 „ 6J ,, „ No. 4 „ II „ „ The Cylinders can be changed in a moment, without unscrewing the rack front from the nozzle of the Lantern, and the Lenses being double combination, give a much sharper and better picture than the ordinary Single Achromatic Lenses. The following are a few examples of the different distances from the screen a lime light Lantern can be placed to give a 10 feet picture with a 3J square photograph with the above Lenses: With the No. i Cylinder a 10 ft. picture can be shown at 21 ft. from the screen. i» 2 »» 11 »» 28 ,, >> 3 >i »i 35 i» >» 4 o ij ^ »» 43 i> A set of Six Coloured Glasses, fitted in Leather Case, is sent with each Patent Rack Front. Prices of the Lenses are as follows :— “New Triple-Rack Telescopic Optical Lantern Objective,” with set of 4 Brass Cylinders, with sliding shutters or flashers, containing Double Combination Achro- matic Lenses (with large size Lenses to the back combination) of the following focii, 4j-in., 6i-in., 9-in., and ii-in., for a single lime-light Lantern, packed in a fitted Mahogany box, with a lock and key, price 6 s. per set. , . For a pair of lime-light Lanterns, or for a Bi-unial Lantern, 2 sets will be required, price £12 I 2 S. the two sets complete, packed in a fitted Mahogany box with lock and key.