| Make |
British Thornton, England |
| Model |
AD 050 Log Log |
| Notes 1.This has the patented Thornton trigonometrical scales.
2. For an article on the "differential" trig scales see the article by John
Mosand (Two Unusual Types of Trigonometric Scales) by John Mosand in the Journal of the
Oughtred Society, Vol. 9, No. 1, Spring 2000.
3. A copy of the instructions for use can be found
here. |
Front view
 |
Detail - front left
 |
Detail - front right
 |
Detail -front - inverse differential sines and
tangents.
 |
Detail -front - differential sines and
tangents.
 |
| Manufacturing date |
>1967. Year British Thornton was formed. |
| Length |
10" |
| Material |
Plastic, Simplex |
| Scales |
LL2,LL3,L,A[B,C1,ISd,ITd,Td,Sd,C]D,S,ST,T |
| Gauge points |
p: 3.14: A,B,C1,C,D
s: C
m: C |
| Cursor |
Plastic |
| Hair lines |
One |