This is an exceptionally rare and highly sought after WWI era Cameron-Yaggi Trench Periscope sighting device that is fitted with an original World War I Springfield Armory Model 1903 bolt action rifle. This specific device was originally developed as a joint venture by J.L. Cameron and L.E. Yaggi towards the end of WWI to enable infantrymen to fire at the enemy while still safely hunkered down inside a trench. This design actually raised the rifle (and its line of sight) approximately two feet up and over a trench parapet, and allowed the infantryman to load and fire the rifle via a mechanical manipulation of the bolt and trigger. For sighting the rifle, it was equipped with a non-magnifying elbow periscope/optical device, which is believed to have been specifically made for the Cameron-Yaggi. The rifle was fitted with a large steel bracket on the left side that has a dovetail in the middle, which allowed this periscope to be attached. It was separate from the actual rifle sights. These rifles were also equipped with a 25-shot magazine that allowed the rifleman to remain in position for sometime before reloading. This design still incorporated the standard leather sling so that the rifle (with the device still attached) could be carried on the infantryman's shoulder. There were three different versions of "Trench Periscope" rifle devices developed during the later days of World War I; two different Cameron-Yaggi devices, the first model (as shown here) and a second later improved design and then a third model that was completely different from the Cameron-Yaggi design, designed by Guiberson. The Guiberson design used a specially designed Model 1903 stock that was "hinged" at the middle barrel band and used a set of reflecting mirrors to sight and fire the rifle. The rifle itself is a standard World War I model that has the standard Springfield Armory receiver markings over serial number and a barrel marking of "SA/4-18/A". It has an all blue straight handled bolt that is marked "J5" on the underside of the safety lug. It has its original front and rear sight set with the dished windage and elevation knobs. It is fitted with an original World War I straight grip "S" style stock with finger grooves on the sides and dual recoil bolts. It has the correct all milled components and a smooth face buttplate. The rifle has its original World War I combination blue metal finish and the oil-quenched casehardened receiver with the color casehardened cutoff and bolt components. There were only a handful of these experimental trench periscope/optical sighting devices (of all three types) ever manufactured with only "5" examples listed in the Springfield Armory museum records; however, this rifle and device was not one of them. This rifle is accompanied by a letter of provenance signed by Herb Rosenbaum who states that he purchased this rifle with trench device directly from Lt. Col. William S. Brophy on February 16th, 1991, one week prior to his passing. This exact rifle in its trench mount is photographed in the following publications by Bruce Canfield: the article "Built for the Trenches" in the January 2003 issue of American Rifleman magazine (scanned copy included), "U.S. Infantry Weapons of the First World War" on pages 110-116, "An Illustrated Guide to the '03 Springfield Service Rifle" on pages 82-90, and this weapon was featured on a 2012 episode of History Channel's "Cajun Pawn Stars". Similar examples of trench rifle designs are shown in the book "The 1903 Springfield Rifle" by Lt. Col William S. Brophy," pages 217-220. Included is a well engineered custom display stand made of steel and wood. Provenance: The William S. Brophy Collection; The Herb Rosenbaum Collection; The Bruce Canfield Collection; The Property of a Gentleman