Triple Prismatic Lathe by Johnson Jex

Triple prismatic lathe made and used by Johnson Jex, 1817-1822.

This is a highly significant, early and interesting multi-purpose machine tool made and used by a locally prominent engineer. Johnson Jex (1778-1852) lived in the village of Letheringsett, Norfolk. He trained as a blacksmith but later acquired additional skills in horology, and tempered his considerable practical abilities with extensive reading on a range of scientific subjects. Surviving written sources indicate that Jex became self-employed c.1817, and in 1822 he advertised the capabilities of his ‘triple prismatic engine lathe’ in the Norfolk Chronicle – these two details provide us with the basis for the date of the lathe’s construction. The lathe is a triangular bar lathe: a treadle base has a column at each corner, with the pair at each end supporting a cast entablature. Between the ends sits the bed frame, consisting of three very robust triangular bars of prismatic section; the principal two of these are approximately 8’ in length. The bars give the lathe exceptional rigidity and provide an excellent mounting for slide rests, etc. The bed supports the working parts of the lathe: head and tailstock, tool rests, a very large dividing head and much else. Jex’s 1822 advertisement claimed a wide range of machining capabilities; from examining the lathe, it is clear that it was developed as a multi-purpose machine, able to be adapted to whatever job Jex had to complete.

Details

Category:
Hand and Machine Tools
Object Number:
2009-67
Materials:
brass (copper, zinc alloy), cast iron, copper (alloy), wood (unidentified) and wrought iron
Measurements:
overall (parts on pallet): 650 mm x 1760 mm x 1470 mm, 441 kg
type:
lathe
credit:
Norfolk Museums and Archaeology Service

Parts

4 Boxes of Components and 4 Wooden Beams of Triple Prismatic Lathe by Johnson Jex

4 Boxes of Components and 4 Wooden Beams of Triple Prismatic Lathe by Johnson Jex

This is a highly significant, early and interesting multi-purpose machine tool made and used by a locally prominent engineer. Johnson Jex (1778-1852) lived in the village of Letheringsett, Norfolk. He trained as a blacksmith but later acquired additional skills in horology, and tempered his considerable practical abilities with extensive reading on a range of scientific subjects. Surviving written sources indicate that Jex became self-employed c.1817, and in 1822 he advertised the capabilities of his ‘triple prismatic engine lathe’ in the Norfolk Chronicle – these two details provide us with the basis for the date of the lathe’s construction. The lathe is a triangular bar lathe: a treadle base has a column at each corner, with the pair at each end supporting a cast entablature. Between the ends sits the bed frame, consisting of three very robust triangular bars of prismatic section; the principal two of these are approximately 8’ in length. The bars give the lathe exceptional rigidity and provide an excellent mounting for slide rests, etc. The bed supports the working parts of the lathe: head and tailstock, tool rests, a very large dividing head and much else. Jex’s 1822 advertisement claimed a wide range of machining capabilities; from examining the lathe, it is clear that it was developed as a multi-purpose machine, able to be adapted to whatever job Jex had to complete.

Triple Prismatic Lathe by Johnson Jex

Triple Prismatic Lathe by Johnson Jex

Triple prismatic lathe made and used by Johnson Jex, 1817-1822.

More

This is a highly significant, early and interesting multi-purpose machine tool made and used by a locally prominent engineer. Johnson Jex (1778-1852) lived in the village of Letheringsett, Norfolk. He trained as a blacksmith but later acquired additional skills in horology, and tempered his considerable practical abilities with extensive reading on a range of scientific subjects. Surviving written sources indicate that Jex became self-employed c.1817, and in 1822 he advertised the capabilities of his ‘triple prismatic engine lathe’ in the Norfolk Chronicle – these two details provide us with the basis for the date of the lathe’s construction. The lathe is a triangular bar lathe: a treadle base has a column at each corner, with the pair at each end supporting a cast entablature. Between the ends sits the bed frame, consisting of three very robust triangular bars of prismatic section; the principal two of these are approximately 8’ in length. The bars give the lathe exceptional rigidity and provide an excellent mounting for slide rests, etc. The bed supports the working parts of the lathe: head and tailstock, tool rests, a very large dividing head and much else. Jex’s 1822 advertisement claimed a wide range of machining capabilities; from examining the lathe, it is clear that it was developed as a multi-purpose machine, able to be adapted to whatever job Jex had to complete.

Object Number:
2009-67/1
type:
lathe
Triple Prismatic Lathe by Johnson Jex

Triple Prismatic Lathe by Johnson Jex

Triple prismatic lathe made and used by Johnson Jex, 1817-1822.

More

This is a highly significant, early and interesting multi-purpose machine tool made and used by a locally prominent engineer. Johnson Jex (1778-1852) lived in the village of Letheringsett, Norfolk. He trained as a blacksmith but later acquired additional skills in horology, and tempered his considerable practical abilities with extensive reading on a range of scientific subjects. Surviving written sources indicate that Jex became self-employed c.1817, and in 1822 he advertised the capabilities of his ‘triple prismatic engine lathe’ in the Norfolk Chronicle – these two details provide us with the basis for the date of the lathe’s construction. The lathe is a triangular bar lathe: a treadle base has a column at each corner, with the pair at each end supporting a cast entablature. Between the ends sits the bed frame, consisting of three very robust triangular bars of prismatic section; the principal two of these are approximately 8’ in length. The bars give the lathe exceptional rigidity and provide an excellent mounting for slide rests, etc. The bed supports the working parts of the lathe: head and tailstock, tool rests, a very large dividing head and much else. Jex’s 1822 advertisement claimed a wide range of machining capabilities; from examining the lathe, it is clear that it was developed as a multi-purpose machine, able to be adapted to whatever job Jex had to complete.

Measurements:
overall: 370 mm x 1820 mm x 1370 mm,
Object Number:
2009-67/2
type:
lathe
Various Parts for the Triple Prismatic Lathe by Johnson Jex

Various Parts for the Triple Prismatic Lathe by Johnson Jex

Various parts for the Triple prismatic lathe made and used by Johnson Jex, 1817-1822. Including Lathe Treadle, Contrate Shaft and Head Stock End.

More

This is a highly significant, early and interesting multi-purpose machine tool made and used by a locally prominent engineer. Johnson Jex (1778-1852) lived in the village of Letheringsett, Norfolk. He trained as a blacksmith but later acquired additional skills in horology, and tempered his considerable practical abilities with extensive reading on a range of scientific subjects. Surviving written sources indicate that Jex became self-employed c.1817, and in 1822 he advertised the capabilities of his ‘triple prismatic engine lathe’ in the Norfolk Chronicle – these two details provide us with the basis for the date of the lathe’s construction. The lathe is a triangular bar lathe: a treadle base has a column at each corner, with the pair at each end supporting a cast entablature. Between the ends sits the bed frame, consisting of three very robust triangular bars of prismatic section; the principal two of these are approximately 8’ in length. The bars give the lathe exceptional rigidity and provide an excellent mounting for slide rests, etc. The bed supports the working parts of the lathe: head and tailstock, tool rests, a very large dividing head and much else. Jex’s 1822 advertisement claimed a wide range of machining capabilities; from examining the lathe, it is clear that it was developed as a multi-purpose machine, able to be adapted to whatever job Jex had to complete.

Measurements:
overall: 670 mm x 1960 mm x 1340 mm,
Materials:
metal (unknown) and wood (unidentified)
Object Number:
2009-67/3
type:
lathe