BRICK EOADS. 39 
ACCEPTANCE AND REJECTION OF MATERIAL. 
Item 15. Basis of acceptance or rejection. — Paving brick shall not be judged 
for acceptance or rejection by the results of individual tests, but by the average 
of not less than five tests. Where a lot of brick fails to meet the required 
average it shall be optional with the buyer whether the brick shall be definitely 
rejected or whether they may be regraded and a portion selected for further 
test as provided in item 16. 
Item 16. Range of fluctuation. — Some fluctuation in the results of the rattler 
test, both on account of variation in the brick and in the machine used in 
testing, are unavoidable, and a reasonable allowance for such fluctuations should 
be made wherever the standard may be fixed. 
In any lot of paving brick, if the loss on a test computed upon its initial 
weight exceeds the standard loss by more than 2 per cent, then the portion 
of the lot represented by that test shall at once be resampled and three more 
tests executed upon it, and if any of these three tests shall again exceed by 
more than 2 per cent the required standard, then that portion of the lot shall 
be rejected. 
If in any lot of brick two or more tests exceed the permissible maximum, 
then the buyer may, at his option, reject the entire lot, even though the average 
of all the tests executed may be within the required limits. 
Item 17. Fixing of standards. — The percentage of loss which may be taken 
as the standard will not be fixed in these regulations, and shall remain within 
the province of the contracting parties. For the information of the public the 
following scale of average losses is given, representing what may be expected 
of tests executed under the foregoing specifications : 
General 
average 
loss. 
Maximum 
permissible 
loss. 
For brick suitable for heavy traffic . . . 
For brick suitable for medium traffic. 
For brick suitable for light traffic 
Per cent. 
22 
24 
26 
Per cent. 
24 
26 
28 
Which of these grades should be specified in any given district and for any 
given purpose is a matter wholly within the province of the buyer, and should 
be governed by the kind and amount of traffic to be carried, and the quality 
of paving brick available. 
Item 18. Culling and retesting. — Where under items 15 and 16 a lot or 
portion of a lot of brick is rejected, either by reason of failure to show a low 
enough average test or because of tests above the permissible maximum, the 
buyer may at his option permit the seller to regrade the rejected brick, sep- 
arating out that portion which he considers at fault and retaining that which 
he considers good. When the regrading is complete the good portion shall 
be then resampled and retested, under the original conditions, and if it fails 
again either in average or in permissible maximum, then the buyer may 
definitely and finally reject the entire lot or portion under test. 
Item 19. Payment of cost of testing. — Unless otherwise specified, the cost 
of testing the material as delivered or prepared for delivery, up to the pre- 
scribed number of tests for valid acceptance or rejection of the lot, shall be 
paid by the buyer. (See also item 23.) The cost of testing extra samples 
made necessary by the failure of the whole lot or any portion of it shall be 
paid by the seller, whether the material is finally accepted or rejected. 
