Wheel Instrument for Vernier Acuity Measurement
Accession Number: 2014.ep.7
Wheel Instrument for Vernier Acuity Measurement
This device is an articulating wheel instrument comprised mainly of iron that has been painted black. A triangular piece of iron is vertically mounted on a horizontal rectangular iron base. The vertical wheel is attached to the triangular stand by a horizontal steel rod. The flat horizontal base, vertical triangular piece, and vertical circular wheel are made of iron that has been painted black.
The wheel has six rectangular openings in it where glass slides would have been inserted. Plastic knobs directly adjacent to all four sides of each opening would have held the slides in place. These knobs are on the side of the wheel opposite the vertical triangular stand. Visible screws on the side of the wheel directly opposite the knobs hold the knobs onto the wheel. Grey pieces of paper are taped adjacent to and slightly covering each of the rectangular openings on the side of the wheel facing the vertical stand. Two of these pieces of paper are torn. Between each rectangular openings, there is a small curved indent in the edge of the wheel. There is a a small metal plate screwed onto the wheel directly adjacent to each indent.
White sticky notes and pieces of yellow masking tape are adhered to the side of the wheel opposite the side that faces the vertical stand. There is one sticky note (or piece of a sticky note) and one piece of masking tape directly adjacent to each rectangular opening, all on the side of the opening closest to the centre of the wheel. The pieces of tape appear to number the slide openings from one to six. The sticky notes are inscribed with letters and numbers corresponding to labels on certain glass slides that accompany the instrument.
An electrical control box is attached to the side of the vertical stand opposite the wheel. The exterior of the box is aluminum with a black panel facing away from the instrument. This panel has a black knob in the centre with the numbers 0 to 100 around it in increments of 10. The electrical box indicates its maker: “CRAMER CONTROLS”. The box also includes the words “TYPE”, “SERIAL”, “POLES”, “MOTOR VOLTS-CY”, “SWITCH”, “SET”, “w.d.” and “RELAY VOLTS-CY”, each with a spot for user inscription based on these categories, but these spots have not been inscribed upon.
Three wires are attached to the bottom of the electrical control box. One is attached to the control box and a metal cylinder adjacent to the box on the side of the box opposite the black knob. Another wire connects the box to a two prong plug. Another wire connects the control box to a speckled metal box which has one large round red button. This speckled box is not attached to the instrument in any other way apart from the wire connecting it to the control box. Another wire is amongst the others, but is not attached to the control box. It is an extension cord with a two-pronged female end and a three-pronged grounded male end, which was presumably used to extend the distance from a plug at which the instrument could be operated.
The steel rod which attaches the wheel to the vertical stand extends through the wheel to a vertical square metal plate on the side of the wheel opposite the stand. This square metal plate is screwed to a vertical aluminum plate below it, which is attached to and directly above a large white vertical rectangular plastic piece. Where the plastic is attached to the metal by two screws, there is an additional empty screw hole, as well as scratches on the aluminium in a half circle pattern, suggesting that a missing part of the instrument at one time scraped against this spot regularly. The large rectangular plastic piece has a glossy finish, is smooth to the touch, and is partially translucent to light.
At the bottom left of the triangular vertical stand, when facing the instrument from the side opposite the wheel, there is a small lever with a spring that connects to a rod on the opposite side of the base. When this lever is pressed, the rod on the side of the base adjacent to the wheel raises and a small round stopper on the end of the rod moves into a position where it could fit into the round indents around the edges of the wheel. If the wheel was in a certain position this rod would hold the wheel in place so that it could not spin.
As well as the wheel instrument, this device came to UTSIC with a wooden box of glass slides. The box currently holds 38 slides and has 2 empty slots, for a capacity of 40 glass slides. This set should be catalogued as 2014.ep.7.2.
Instrument: Iron, Aluminum, Other Metal, Glass, Plastic, Paper. Box: Wood. Slides: Glass.
A plate is screwed onto the metal cylindrical piece that attaches the wheel to the vertical stand. This plate indicates manufacturing and patent information for the ball bearing encased in this piece:
PAT2,403.687 OTHERS PEND
SHAFT 1/2“ BALL BRG. SFT UNIT 8″
Most of the glass slides have white stickers adhered to one of their corners. These stickers are inscribed with writing in the format of the following: “SG L.65″, “BG L.75”, “SG R.85”, “BG L.95”.
Pieces of masking tape adhered to the wheel are inscribed with the numbers 1 through 6. Sticky notes adhered to the wheel are inscribed with numbers and letters corresponding to labels on certain glass slides that accompany the instrument.
Height = 70, Width = 61, Length = 40.5, Diameter of wheel = 66, Box of glass slides: Height = 13.5, Width = 37.5, Length = 30.5
This instrument was used for measuring vernier acuity. The subject sits at a set distance from the wheel and views one of the glass plates at a time. The presentation of the glass slides is controlled by the wheel rotating and presenting the subject with one plate at a time based on a predetermined presentation formula. Each glass plate has a set of lines on it. The subject’s task is to say whether or not the lines on various slides are offset or exactly lined up. This test is analogous to what would be done by someone reading a vernier scale. The analysis of the data resulting from this test is done using standard techniques of psychophysics.
The information about the function of this instrument was provided by Professor Paul Milgram at Engineering Psychology in the University of Toronto’s Faculty of Applied Science and Engineering.
Overall, the instrument is in fair condition, but not in an operable state.
The black paint is worn off near the outer edges of the wheel and around the large rectangular holes in the wheel. The areas with worn paint appear almost exclusively on the side of the wheel which faces the electrical control box. The areas where the paint is worn reveal a metallic surface underneath.
Two of the pieces of paper which are taped partially over the rectangular holes in the wheel are torn.
The plastic outer layer on the wire which connects the control box to the two-pronged plug is cracked and worn off at numerous points along the wire.
One of the prongs on the three-pronged extension cord plug is bent.
There is evidence of a missing part on the vertical rectangular aluminum piece that is attached to and directly above the large white rectangular plastic piece. Where the plastic is attached to the metal by two screws, there is an additional empty screw hole, as well as scratches on the aluminium in a half circle pattern, suggesting that another part of the instrument scraped against this spot numerous times.
Dust has settled on most surface areas of the instrument.
The object should be cleaned off to remove dust. The 3 wires should be untangled and moved out of their current location, which is through one of the rectangular holes in the wheel, so that the wheel can be turned if desired.
There are many layers of tape and sticky notes on the wheel, which could be removed if desired. Most of these items are attached to the side of the wheel opposite the vertical stand and control box.
It is necessary that two individuals cooperate to pick up or move the instrument because of its size and weight.
No attempt should be made to operate the instrument without repairing the wires and consulting an electrician or other individual knowledgeable in electrical safety.
Unknown. It is likely that the instrument was custom made for Professor Patrick J. Foley.
Date of Manufacture: 1966-2000
The original owner of this instrument was Professor Patrick J. Foley, who joined the University of Toronto’s Department of Industrial Engineering in 1966.
This object was acquired by the University of Toronto Scientific Instruments Collection in October of 2012 from the laboratory of Professor Paul Milgram at Engineering Psychology in the University of Toronto’s Faculty of Applied Science and Engineering.
1) Zu, Jean. 2011. “Memorial Tribute to Patrick J. Foley: Professor Emeritus in the Department of Mechanical and Industrial Engineering.” Faculty of Applied Science and Engineering Council Minutes. http://www.engineering.utoronto.ca/Assets/AppSci+Digital+Assets/pdf/faculty+council+minutes/Memorial+Tribute+to+Patrick+Foley.pdf [Retrieved March 4, 2014].
Information about the function and origin of this instrument was provided in correspondence with Professor Paul Milgram in February, 2014. Professor Milgram works in Engineering Psychology in the University of Toronto’s Faculty of Applied Science and Engineering.
Donated to UTSIC: Yes
This instrument was used by Professor Patrick J. Foley, who joined the University of Toronto’s Department of Industrial Engineering in 1966. The manufacturing date range for the instrument is based on Professor Foley’s career at the University of Toronto.
A search has been conducted in the University of Toronto’s library catalogue, but no works written by Professor Patrick J. Foley have been found that pertain to this instrument.