full moon by Horace Dall
1920-1929
Early stereoview of Horace Dall
circa 1920
Horace Dall observatory
1961-1979
'totality' at a solar eclipse
1970-1989
tin stereoviewer
1920-1929
Dall-Kirkham reflecting telescope, 1960-1975
1960-1975
Dall-Kirkham Cassegrain reflecting telescope of folding design
1974
Modified Maksutov reflecting telescope
1960
projected view of the centre of the town of Luton at sunset through a camera obscura
1960-1979
Horace Dall observatory
1960-1979
Airship R101 over Southern England
1929-1930
Pocket Gregorian Telescope
Diffraction Series
1964
stereoviews
Folding telescope designed by Horace Dall
1960-1975
Occultation reaction timer
1950-1975
Stereoscope plus stereo pictures
Subminiature Foucault knife-edge tester
1950-1975
Spider-web forks in envelope
Drawing-board
Radius measurer, plus older two-lamp radius gauge
1950-1975
Micro-monochromator
1950-1975
Small refractometer
1950-1975
Box of mixing prisms to demonstrate blooming
1950-1975
Catadioptric reflecting telescope
1960-1975
"Introscope" in box
1950-1975
Micromanometer in box
1950-1975
Spherometer in box with accessories
Sidereal clock, electrically driven
1950-1975
Spectrograph
1960-1975
Refractometer
1950-1975
Constant-deviation spectroscope
1950-1975
Spherometer
1950-1975
Maksutov reflecting telescope
1961
Dall-Kirkham Cassegrain reflecting telescope
1960-1975
Maksutov reflecting telescope
1960-1975
Ten-inch Newtonian telescope made by Horace Dall
1933-1937
Maksutov telescope by Horace E. Dall
1960-1980
Maksutov reflecting telescope
1960-1975
Maksutov reflecting telescope
1960-1975
Two self-marking Knife-edge Foucault testers
1950-1975
Experimental and lens-grinding apparatus
Tripod mirror-grinding table with glass top
1950-1975
Three microspherometers plus box of wire
Mercury switch (Hg enclosed) mounted on white friable board
Three spring balances
Graticule engraver
1950-1975
Refracting telescope of aperture 18cm
1960-1980
Slit spectroscope
1950-1975
Radiation measuring apparatus: five items
1950-1975