]12 PHILOSOPHICAL TRANSACTIONS. [anNO l684-5. 



and when fixed in that situation, I poured water into one of the vessels, till 

 the orifice of the siphon was a little immersed in it, and presently, as I ex- 

 pected, the water ran out into the other vessel. Then that vessel being emptied 

 into which I had first poured water, I poured it into the other, and immediately 

 that water ran back into the first vessel. Though I would not venture to com- 

 pare the artifice of this siphon of mine with that of Wurtemburg, yet I expect 

 it may prove little less useful, especially if combined with another instrument 

 of my contrivance. 



Description of a Siphon performing the same Things as the Wurtemburg Siphon. 

 By Dr. Papin, F.R.S. Translated from the Latin. N° 167, p. 847. 



In the treatise on the Wurtemburg siphon, which was lately printed at Stut- 

 gard by M. Solomon Reisel, some wonderful effects are related of that new 

 siphon, the characteristic properties of which are stated to this eff'ect ; 1 . That the 

 orifices of the two legs are placed on the same horizontal line within the brims 

 of the vessels. 2. That though the orifices be but in part or the half filled 

 with water, yet the water flows out drawn over a mountain. 3. Though the 

 machine may have been at rest and dry for a long time, yet it will again produce 

 its eflrect on the application of water. 4. That either of the orifices being 

 opened, and the other remaining shut for hours, or a whole day, when this is 

 afterwards opened, the water will flow out. 5. That though the orifices be 

 both on a level, and the legs of an equal height, yet the water will flow out. 

 6. That the water rises and falls indifferently through either leg. 



But as the author gives no explanation how the machine is made to produce 

 these notable effects, the Royal Society desired me to construct a machine, 

 which might exhibit the same phaenomena as those above-mentioned. This I 

 have effected after three several ways, the simplest and easiest of which seems 

 to be the following. 



AA, fig. 10, pi. 3, are two metallic vessels, into which the two extremities of 

 the siphon are inserted. BCDEDCBis a siphon, having its orifices BB placed 

 on the same horizontal line or level. F is a little tube soldered into the hole 

 in the top of the siphon, and to be carefully stopped after the siphon is quite 

 filled with water. Now it is plain that the water contained in the parts CD will 

 prevent the admission of the external air to the upper part of the siphon, E, 

 So that the siphon being always full of water, provided it do not exceed a cer- 

 tain height, it will certainly produce its effect, as soon as the water in the vessels 

 A A shall fill some part of either orifice B. And both orifices being partly filled 

 with water, when in each vessel A the surface of the water shall be in the same 

 horizontal line or level, if ever so little water be poured into either vessel, part 



