Casgliadau Arlein

A circular platform/walkway held at right angles to an axle. Dogs walking on the platform produced a rotary motion. In the Gallery of Material Culture the object was displayed with a transmission (cog, shaft, and two bearings) connected to a box churn (29.132). From the accession record it is unclear whether the transmission was part of the original accession or not but in the absence of any information to the contrary it has been treated as part of this object. On display the wheel was fixed at an angle of between 45 and 30 degrees. The walkway is made in 8 sections, each section is numbered (1- 8) with a brass disc nailed to its underside. The discs would have been attached prior to dismantling by the Museum. Each section of walkway is constructed from 4 lengths of tongued and grooved boards. The outer board on each section is curved so that a circle is produced overall, whilst the inner boards are straight edged so the hole in the centre of the wheel is octagonal. Grip for the dogs is provided by four lengths of half round beading spanning the full width of each walkway section (max = 560mm) alternating with four shorter (290 - 300mm) lengths positioned towards the outer edge. The beading is nailed to the T&G. The ends of each walkway section are suported by spokes (8 in total) radiating from the central axle and the outer board is also supported from below by a batten (17 x 18mm) nailed between the ends of the spokes. The spokes fit into the axle with stopped mortice and barefaced tennon joints (the tennon has only one shoulder). Additional support for the spokes is provided by 9mm diameter iron rods, bolted (coach bolts) through the spokes 450mm from the axle at one end and screwed towards the top of the axle at the other. These rods vary in length and the ends vary in shape and size, some being fixed with one others with two screws. The rods are painted grey. The axle has a circular cross section at its ends but is octagonal in section for most of its length and gets thicker towards the middle. The top and bottom of the axle have iron rings around the wood and iron stub axles inserted into the ends. The stub axle at the top has a flat end and protrudes by 122mm (4"), at the bottom the stub axle protrudes 85mm and has a pointed end. Below the walkway 810mm from the axle there are 8 (57mm wide, 35mm deep) curved pieces of wood (cog beams) bolted through their centres to the bottom of each spoke. coach bolts were used to hold three of the sections and large nails that have had their ends threaded were used to hold the remaining five sections. All of the coach bolts and one of the threaded nails have been treated with a rust converter and are most likely original. Three of the threaded nails are not corroded and have not been treated with a rust converter and are most likey replacements made during restoration. The cog beam sections are joined at their ends by a (207mm long, 19mm wide) strip of metal with a screw in each end. The result is a circle (approx 850mm radius) of wooden batten below the walkway. Attached to the bottom of this circle are 8 curved sections of toothed (28 teeth per section) iron rail (cog rail sections). Each section is attached by 3 bolts. Some of these bolts are also threaded nails and again some appear to be original and others replacement parts. Some of the original bolts and threaded nails have replacement square nuts. Some of the bolts have washers between the nut and the wood. The ends of the cog rail sections meet at the spokes. This produces a large cog (approx radius 870mm) below the wheel, which allows the rotaray motion produced by the work of the dogs to be transfered to the transmission. On display this cog meshes with a solid cast iron 27 tooth (230mm diameter) cog attached to a length of shafting (painted grey) bolted to a trestle by two cast iron bearings. It can not be said for certain that any of the transmission is original to the dog wheel. The shafting may be original and unaltered but it seems at least as likely that it has been cut down to size for dispaly purposes or it could be a complete fabrication or from some other source. The end of the shaft is square in section and has been drilled to accept a bolt used to attach two iron strips which provided an improvised linkage to the box churn (29.132) dispalyed with the dog wheel. The object was displayed mounted on shaped blocks of oak, these were removed and stored with the object as although they are unlikely to be part of the original object their shapes may have been based on the originals.