produced by a Fluid in Motion. 



217 



No one who lias fired a gun into water can have failed to 

 observe the numberless bubbles of air which rise to the surface 

 for a few seconds after the penetration of the shot. Each shot 

 ploughs for itself a channel, into which air enters, is enclosed by 

 the water, and penetrates to a greater or less depth according as 

 the velocity of the shot is considerable or otherwise. 



Let us now pass on to the experiments made with the appa- 

 ratus described above. 



The number of seconds required by half a litre of water to 

 flow from the delivery-tube H, and the number of seconds 

 required by that water to carry down half a litre of air, being 

 determined in the manner stated above, the number of cubic 

 centimetres of air carried down by half a litre of water could 

 obviously be readily calculated. Each of the results given below 

 is the mean of several determinations — generally of ten, except 

 in those cases in which four or five consecutive determinations 

 gave absolutely similar results. 



Circular delivery-tube (H, fig. 1) - 2 V ns °f an ^ ncn internal 

 diameter. (The comparative dimensions of the delivery-tube 

 and the vertical tube B are shown full size at A, fig. 2.) 

 Flow = half a litre of water in 24 seconds. 









Quantity of air 





Quantity of air 









carried down by 





carried down 





Depth of water 





half a litre of 





when the orifice 



Level of water main- 



maintained con- 



Order of 



water when the 



Order of 



of the tube deli- 



tained constant in A 



jstant in D during 



experi- 



orifice of the tube 



experi- 



vering the air 



during the experiment 



\ the experiment!" 



ments. 



delivering the air 



(c, fig. lj 



= 8 ths of an 



inch in diam. 



ments. 



(c, fig. 1) 

 =_J_th of an 

 inch in diarn. 



At 2 inches below 



1 











the orifice of B 



I 1 inch. 



1. 



615 cub. cent. 



16. 



136 cub. cent. 



(«,fig- 1) 



J 











At 1 inch below 



1 











the orifice of B 



Y » 



2. 



615 



17. 



136 



(Mg-1) 



J 











At the orifice of B 

 (*.fig.l) 



} » 



3. 



545 



18. 



137 „ 



At 1 inch above 



l 











the orifice of B 



\ » 



4. 



201 



19. 



132 „ 



(*,fig;.i) 



J 











At 2 inches above 



1 











the orifice of B 



r » 



5. 



174 „ 



20. 



182 „ 



(e, fig. 1) 



J 











At a, fig. 1 



j 



inches. 



6. 



153 



21. 



122 



» b> m 



>> 



7. 



153 



22. 



122 



Q 





8. 



167 



23. 



113 „ 



d 



H 



9. 



*"* it 



157 



24. 



178 „ 



e " ...... 



}> 



10. 



125 



25. 



171 



,, a, ,, 



5 inches. 



11. 



130 



26. 



171 „ 







12. 



130 



27. 



171 



c " r....... 



>> 



13. 



125 



2 A. 



• * *■ tt 

 171 » 



,, d, ,, 



>> 



14. 



113 „ 



118 „ 



29. 



166 



,, e, ,, ■ 



>> 



15. 



30! 



165 „ 







Phil. Mac/. S. 4. Vol. 28. No. 188. Sept. 1864. 



Q 



