# John Allen Harker

> English director of research at the Ministry of Munitions and chief assistant at the National Physical Laboratory (1870-1923)

**Wikidata**: [Q21165591](https://www.wikidata.org/wiki/Q21165591)  
**Source**: https://4ort.xyz/entity/john-allen-harker


## References

1. [Source](http://discovery.nationalarchives.gov.uk/details/r/C6369)
2. [Source](http://www.twickenhamurc.org.uk/history/whoswho.htm)
3. [Source](http://discovery.nationalarchives.gov.uk/details/record?catid=4859&catln=3)
4. [Source](http://www.jstor.org/stable/1648609)