TY  - BOOK
AU  - Heather,John Fry
AU  - Walmisley,Arthur Thomas
TI  - A treatise on mathematical instruments: their construction, adjustment, testing, and use 
T2  - Weale's scientific and technical series
PY  - 1888///
CY  - London
PB  - C. Lockwood and son
N1  - Indice
ER  -