32 BULLETIN 246, U. S. DEPARTMENT OF AGRICULTURE. 
on the street when delivered ready for use. When the quantity under consider- 
ation exceeds 100.000. the sampling shall be done at the factory prior to ship- 
ment. Brick accepted as the result of tests prior to shipment shall not be 
liable to subsequent rejection as a whole, but are subject to such culling as is 
provided for under Section II (Visual inspection). 
Item 2. Method of selecting samples. — In general the buyer shall select his 
own samples from the material which the seller proposes to furnish. The seller 
shall have the right to be present during the selection of a sample. The sampler 
shall endeavor, to the best of his judgment, to select brick representing the aver- 
age of the lot. No samples shall include brick which would be rejected by 
visual inspection as provided in Section II, except that where controversy arises, 
whole tests may be selected to determine the admissibility of certain types or 
portions of the lot having a characteristic appearance in common. In cases 
where prolonged controversy occurs between buyer and seller, and samples 
selected by each party fail to show reasonable concurrence, then both parties 
shall unite in the selection of a disinterested person to select the samples, and 
both parties shall be bound by the results of samples thus selected. 
Item 3. Number of samples per lot. — In general one sample of 10 brick shall 
be tested for every 10,000 brick contained in the lot under consideration, but 
where the total quantity exceeds 100,000, the number of samples tested may be 
fewer than 1 per 10,000, provided that they shall be distributed as uniformly 
as practicable over the entire lot. 
Item 4. Shipment of samples. — Samples which must be transported long dis- 
tances by freight or express must be carefully put up in packages holding not 
more than 12 brick each. When more than six brick are shipped in one 
package, it must be so arranged as to carry two parallel rows of brick side by 
side, and these rows must be separated by a partition. In event of some of 
the brick being cracked or broken in transit, the sample shall be disqualified 
if there are not remaining 10 sound undamaged brick. 
Item 5. Storage and care of samples. — Samples must be carefully handled to 
avoid breakage or injury. They must be kept dry so far as practicable. If 
wet when received, or known to have been immersed or subjected to recent pro- 
longed wetting, they shall be dried for at least six hours in a temperature of 
100° F. before testing. 
THE CONSTRUCTION OF THE RATTLER. 
Item 6. The machine shall be of good mechanical construction, self-contained, 
and shall conform to the following details of materials and dimensions, and 
shall consist of barrel, frame, and driving mechanism as herein described. 
Accompanying these specifications is a complete drawing (PI. X) of a rattler 
which will meet the requirements ,and to which reference should be made. 
Item 7. The barrel. — The barrel of the machine shall be made up of the heads 
and head liners and staves and stave liners. 
The heads may be cast in one piece with the trunnions, which shall be 2£ 
inches in diameter and shall have a bearing 6 inches in length, or they may be 
cast with heavy hubs, which shall be bored out for 2iVinch shafts, and shall 
be keyseated for two keys, each i inch by f inch and spaced 90° apart. The 
shaft shall be a snug fit, and when keyed shall be entirely free from lost motion. 
The distance from the end of the shaft or trunnion to the inside face of the 
head shall be 15f inches in the head for the driving end of the rattler and 
llf inches long for the other head, and the distance from the face of the hubs 
to the inside face of the heads shall be 5& inches. 
