The Reversible Rose: Turn the Sprinkler Round and the Water Clears It

"The spout of a watering-pot, of the ordinary construction, is provided with a stationary perforated 'rose,' or nozzle, through which the water passes in jets upon the ground, plant, or other article or place to be sprinkled." "Owing to extraneous matter contained in the water, the perforations become closed, and the water ceases to flow until the obstruction is removed, which operation is tedious, and inconvenient to perform." The perforated plate crosses the middle of a ring threaded at both ends, so that when the perforations "become clogged by obstructions collecting on the inner face of the plate, the band may be unscrewed, and its position reversed, when it can be readily returned to its place, the force of the water within the watering-pot being sufficient to instantly wash away the obstruction." He adds that it "may also be applied to a syringe or sprinkler for clothes, or other purposes".

Fill a watering can with 5 litres, hold it at a steady tilt over a bucket, and time how long it takes to empty through the rose. Count the holes in the rose. Tape over a fifth of the holes from the inside and time it again; then two fifths. Compare how the time grows with the notebook. Finally sprinkle a pinch of fine sand into the can, pour, and watch the holes clog; take the rose off, turn it round if it can be, and see whether the water clears it.

**James Barrows** of Hyde Park, Norfolk County, Massachusetts, received US 87,321, dated 2 March 1869. **Honest limits.** The flow model treats every hole as the same simple orifice under a steady head; in a tilted can the head changes as it empties, and partly blocked holes are not simply open or shut. Sizes and counts are examples. Your stopwatch times are the measurement.