The Samuel Oschin Telescope

Since 1949 the 48-inch (1.2 m) Samuel Oschin Telescope has been quietly working to improve our understanding of the universe. It nightly scans the skies, returning discoveries that astound and amaze. Currently it operates as a robotic telescope. The data collected is beamed out by microwave via the High Performance Wireless Research and Education Network to astronomers for analysis.
The current main research project performed with this telescope is known as the Palomar Transient Factory (PTF). For more see Palomar Transient Factory on Wikipedia or the press release on PTF from Caltech and Berkeley.
It is a wide-field Schmidt telescope that was designed for survey work. The telescope has a 48-inch aperture with a glass corrector plate and a 72-inch (f/2.5) mirror. Russell Porter's 1941 drawing of the telescope.
A brief history of the Samuel Oschin Telescope

Images of the Samuel Oschin Telescope
Discoveries made at the 48-inch Samuel Oschin Telescope
Digital Palomar Observatory Sky Survey Images in Google Sky
The Samuel Oschin Telescope was used to generate the Second Palomar
Observatory Survey
POSS II and the Digital Palomar Observatory Sky
Survey DPOSS.
Plates for the POSS II survey were donated by the
Eastman Kodak Corporation.
The POSS II survey was enabled by grants from the
Alfred P. Sloan Foundation,
the
National Geographic Society, and the
National Science Foundation.
Partial funding for the DPOSS survey
was provided by the Norris Foundation.
Plates were scanned at the
Space Telescope Science Institute, and the results catalogued
at Caltech.
URL for POSS II:
http://www.astro.caltech.edu/~wws/poss2.html/
URL for DPOSS:
http://www.astro.caltech.edu/~george/dposs/
Samuel Oschin Telescope Surveys at Palomar Observatory - How are objects like dwarf planet Eris discovered?
Hunting Gamma-Ray Bursts with the Samuel Oschin Telescope
Technical details on the QUEST camera
Eleanor Helin's Career & Asteroid Searches from Women In Technology
5391 Emmons the story of how an asteroid discovered at Palomar by Eleanor Helin got its name.
High Performance Wireless Research and Education Network
The Big Picture now on display at Griffith Observatory