![](https://coimages.sciencemuseumgroup.org.uk/461/506/large_thumbnail_smg00027727.jpg)
![](https://coimages.sciencemuseumgroup.org.uk/461/506/large_thumbnail_smg00027727.jpg)
![](https://coimages.sciencemuseumgroup.org.uk/461/508/large_thumbnail_smg00027730.jpg)
Twaddell's No. 6 hydrometer, scale 138-170.
![](https://coimages.sciencemuseumgroup.org.uk/461/507/large_thumbnail_smg00027729.jpg)
Twaddell's No. 4 hydrometer, scale 74-102.
![](https://coimages.sciencemuseumgroup.org.uk/316/790/large_thumbnail_smg00027790.jpg)
Twaddell no 1 hydrometer
1920-1960
![](https://coimages.sciencemuseumgroup.org.uk/449/511/large_thumbnail_smg00027768.jpg)
Twaddell hydrometer
1920- 1960
![](https://coimages.sciencemuseumgroup.org.uk/321/578/large_thumbnail_smg00026700.jpg)
Twaddell no 6 hydrometer
1920-1960
![](https://coimages.sciencemuseumgroup.org.uk/449/505/large_thumbnail_smg00027762.jpg)
Twaddell no 4 hydrometer
1920-1960
Twaddell's No. 3 hydrometer, scale 48-74 (broken).
Glass Twaddles' hydrometer
Twaddell 0/6 hydrometer
Twaddell no 4 hydrometer
1900-1960
Twaddell no 1 hydrometer
1900-1970
Twaddell no 6 hydrometer
1920-1960
Glass Twaddle hydrometer
Twaddell no 4 hydrometer
1920-1960