burning glass
LowTechnical, historical, literary
Definition
Meaning
A convex lens that concentrates the sun's rays to create intense heat and set combustible materials on fire.
A device, historically often a lens, used to focus light or energy to produce a powerful, concentrated effect; metaphorically, something that concentrates attention or intensity on a particular point.
Linguistics
Semantic Notes
A compound noun referring specifically to a physical object with a historical and technical function. It is not typically used to refer to modern magnifying glasses used for general viewing.
Dialectal Variation
British vs American Usage
Differences
The term is identical in spelling and meaning. Usage is equally rare in both varieties, largely confined to historical or scientific contexts.
Connotations
Both carry the same primary technical/historical connotation. In literary use, it may metaphorically suggest intense focus or scrutiny.
Frequency
Extremely low frequency in modern everyday language. Slightly higher likelihood of encounter in British historical texts due to older scientific traditions.
Vocabulary
Collocations
Grammar
Valency Patterns
[Subject] used a burning glass to [verb] [object]The [material] was ignited by a burning glass.Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “No common idioms directly use 'burning glass'. Metaphorical: 'a burning glass of criticism'.”
Usage
Context Usage
Business
Virtually never used.
Academic
Used in history of science, physics (optics), and historical literature studies.
Everyday
Extremely rare. Might be used by hobbyists in historical reenactment or survivalism.
Technical
The precise term for the historical instrument in optics and scientific history.
Examples
By Part of Speech
verb
British English
- He attempted to burning-glass the dry tinder, but the sun was too weak.
American English
- They tried to burning-glass the paper, using the lens from a flashlight.
adjective
British English
- The burning-glass demonstration was the highlight of the Victorian science fair.
American English
- He explained the burning-glass principle to the fascinated students.
Examples
By CEFR Level
- A burning glass uses the sun to make fire.
- In the old days, people sometimes used a burning glass to light a campfire.
- The museum exhibit featured an 18th-century burning glass, demonstrating how early scientists concentrated solar energy.
- The critic's analysis acted as a burning glass, focusing relentless intellectual heat on the flaws in the author's central thesis.
Learning
Memory Aids
Mnemonic
Think of a glass (lens) whose sole job is burning things by focusing the sun.
Conceptual Metaphor
CONCENTRATION IS A LENS / INTENSE FOCUS IS HEAT.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Avoid translating as 'горящее стекло' (glass that is on fire). The correct conceptual translation is 'зажигательное стекло' or 'линза для зажигания'.
Common Mistakes
- Using it to mean any magnifying glass. Confusing it with 'burning' as an adjective (e.g., 'a glass that is burning').
Practice
Quiz
What is the primary function of a burning glass?
FAQ
Frequently Asked Questions
Not exactly. While all burning glasses are magnifying lenses, the term 'burning glass' specifies its historical purpose of igniting fires. A modern magnifying glass is primarily for viewing enlargement.
No, it is an archaic term. You might encounter it in historical texts, museums, or discussions about the history of science and optics.
Yes, though it's a literary device. It can describe something that focuses attention or intensity to a powerful degree, e.g., 'Her testimony was a burning glass on the corruption scandal.'
A burning glass is a lens that refracts (bends) light to a focal point. A burning mirror (like Archimedes' legendary device) is a concave mirror that reflects and concentrates light to a point.