# Canonical recap data for Carnegie Steel Mill Opens (1875)
# Source: https://recap.at/1875/carnegie-steel-mill
# Format: YAML 1.2 (UTF-8). Generated at request time.
slug: carnegie-steel-mill
canonicalUrl: "https://recap.at/1875/carnegie-steel-mill"
title: Carnegie Steel Mill Opens
subtitle: Andrew Carnegie's Edgar Thomson Works introduced the Bessemer process to American steelmaking at scale, triggering industrial transformation and labor upheaval.
recapType: global_event
eventStatus: concluded
startDate: 1875-01-01
datePrecision: year
year: 1875
decade: 1870
country:
name: United States
slug: united-states
summaryShort: "The Carnegie telescope is a twin 20-inch (510 mm) refractor telescope located at Lick Observatory in California, United States. The double telescope's construction began in the 1930s with a grant from the Carnegie institution, although it was not completed until the 1960s when a second lens was added. The telescope is "
summaryLong: The Carnegie telescope is a twin 20-inch (510 mm) refractor telescope located at Lick Observatory in California, United States. The double telescope's construction began in the 1930s with a grant from the Carnegie institution, although it was not completed until the 1960s when a second lens was added. The telescope is not designed for visual observation, rather it has two lenses used for taking photographs for a specific wavelength recorded on a film emulsion. It was used for photographic sky surveys in the late 20th century, which were successfully completed.
heroImageUrl: "https://upload.wikimedia.org/wikipedia/commons/thumb/0/03/Carnegie_telescope_dome%2C_Aug_2019.jpg/1280px-Carnegie_telescope_dome%2C_Aug_2019.jpg"
heroImageCredit: Wikipedia · "Carnegie telescope"
importance: 81
sourceConfidence: 75
keyFacts: []
timeline: []
sources:
- url: "https://en.wikipedia.org/wiki/Carnegie_telescope"
  title: Carnegie telescope
  provider: Wikipedia
related: []
categories:
- tech-launch
metaDescription: The Carnegie telescope is a twin 20-inch (510 mm) refractor telescope located at Lick Observatory in California, United States. The double telescope's construct
wikidataQid: Q5043985
archiveSnapshots:
- url: "https://web.archive.org/web/20260110115733/https://en.wikipedia.org/wiki/Carnegie_telescope"
  capturedAt: 2026-01-10
  label: Carnegie telescope
  originalUrl: "https://en.wikipedia.org/wiki/Carnegie_telescope"
