| Name and Model Number | Baines slide rule No. 1 |
| Country of Origin | United Kingdom |
| Date of Manufacture | Patented 1903 |
| Front Scales | Velocity, Loss of head, Pipe diameter, Discharge in GPM, Discharge in CuFt/Sec |
| Back Scales | |
| Scale Length | 23.5 cm |
| Type of Rule | Slide Rule |
| Construction | Four wooden members kept aligned by a brass pantograph on the back |
| Area of Use | Other |
| Comment | An unusual device that uses the pantograph linkage to keep the four scales at equal separation.
Used for hydrological calculations using Flamant's formula. |
| Rarity | RRR |
| Donor | Collection of Nathan Zeldes |
| Match Number | 410 |
| Thumbnail (Click Picture for Details) |  |
| In conjunction with our 'donors' we assign a rarity rating to each item, based on the system devised by Herman van Herwijnen |
| (1929 - 2004), renowned Dutch collector, author, and creator of Herman's Archive, a collection of 5,000 slide rule images on CD. |
| • RR = Rare - 1 of 25 collectors has one; it may take a year to find an example in the marketplace. |
| • RRR = Very Rare - only a few known to collectors; may be several years before it comes up for sale. |
| • RRRR = Extremely Rare - a museum piece; unlikely that an example will come up for sale. |