127 



(1.57 in.) high, resting on a glass plate J, about 10 

 cm. (3.94 in.) square. 



18. In making the determination, the same quantity 

 of cement as will be subsequently used for each batch in 

 making the briquettes (but not less than 500 grams) is 

 kneaded into a paste, as described in paragraph 39, and 

 quickly formed into a ball with the hands, completing 

 the operation by tossing it six times from one hand to 

 the other, maintained 6 in. apart; the ball is then pressed 

 into the rubber ring, through tiie larger opening, smoothed 

 off, and placed (on its large end) on a glass plate and 

 the smaller end smoothed off with a trowel; the paste, 

 confined in the ring, resting on the plate, is placed under 

 the rod bearing the cylinder, which is brought in contact 

 with the surface and quickly released. 



19. The paste is of normal consistency when the cylin- 

 der penetrates to a point in the mass 10 mm. (0.39 in.) 

 below the top of the ring. Great care must ^e taken to 

 fill the ring exactly to the top. 



20. The trial pastes are made with varying percentages 

 of water until the correct consistency is obtained. 



Note. The Committee on Standard Specifications in- 

 serts the table on page 121 for temporary use to be re- 

 placed by one to be devised by the Committee on the 

 American Society of Civil Engineers. 



Time of Setting. 



21. Method: For this purpose the Vicat Needle, which 

 has already been described in paragraph 17, should be 

 used. 



22. In making the test, a paste of normal consistency 

 is molded and placed under the rod /.. I i_r. L', as de-- 

 scribed in paragraph 18; this rod. bearing the cap /> at 

 one end and the needle //, 1 mm. m. <:'.'. in.i in diameter, 

 at the other, weighing 300 gr. (10.58 oz.). The needle is 

 then carefully brought in contact with the surface of the 

 paste and quickly released. 



23. The setting is said to have commenced when the 

 needle ceases to pass a point 5 mm. (0.20 in.) above the 

 upper surface of the glass plate, and is said to have ter- 

 minated the moment the needle does not sink visibly into 

 the mass. 



24. The test pieces should be stored in moist air during 

 the test; this is accomplished by placing them on I 

 over water contained in a pan and covered with :i .l.imp 



