If a published table of discounts cannot be procured, the estimator may make one to include whatever range of discounts may be desired. There are very handy tables published, which show discounts from 10% up to 85%. These tables are arranged in the following manner, which may be followed or modified by the estimator in working out his own table of discounts:

Discount - Per Cent

Decimal Equivalent

Net Amount or Multiplier

25 -

.25

•75

.. 25 - 2 1/2

.2688

.7313

25 - 2 1/2 - 2 1/2

.2870

.7130

25 - 21/2 - 5

.3053

.6947

25 - 21/2 - 71/2

.3236

.6764

25 - 2 1/2 - 10

. 3419

.6581

25 - 5

.2875

.7125

25 - 5 - 2 1/2

.3053

.6947

25-5-5

.3231

.6769

25 - 5 - 7 1/2

.3409

.6591

25 - 5 - 10

.3588

.6413

25 - 7 1/2

.3063

.6938

25 - 7 1/2 - 2 1/2

.3236

.6764

25 - 7 1/2 - 5

. 3409

.6591

25 - 7 1/2 - 7 1/2

.3583

.6417

25 - 7 1/2 - 10

.3756

.6244

25 - 10

.3250

.6750

25 - 10 - 2 1/2

.3419

.6581

25-IO-5

.3588

.6413

25 - 10 - 7 1/2

.3756

.6244

25 - 10 - 10

.3925

.6075

25 - 10 - 10 - 5

.4229

.5771

27 1/2

.275

.725

27 1/2 - 2 1/2

.2931

.7069

27 1/2 - 2 1/2 - 2 1/2

.3108

.6892

The amounts in the column of decimal equivalents simply show the value of the different discounts when reduced to decimals. A comparison of decimal equivalents will show that in some cases different discounts really mean the same thing.

Thus the discount 25 - 2 1/2 - 7 1/2 is of just the same value as the discount 25 - 7 1/2 - 2 1/2.

In connection with the subject of estimating, no attempt will be made to give instructions concerning the estimating of labor. The author appreciates the fact that this information will be sought fully as much as any that has been given, but an attempt at advising the figuring of certain amounts of time for certain amounts of work will be misleading, and no doubt, if followed, might lead to trouble, especially among new estimators of insufficient experience to allow for various different conditions. For instance, the methods of construction and the choice of material varies considerably in different parts of the country, and, furthermore, much depends upon the workmen themselves, some doing a far greater amount of work per day than others. Labor is certainly the most difficult item to estimate, so many conditions entering into the matter. In many towns and cities certain classes of building construction are very general. For instance, in certain cities three-flat houses may be universally used, while in another two-flat and six-flat houses may be the rule. The plumber who has much of such work to do soon learns from experience the amount of labor necessary to figure, almost to an hour, and, in fact, is often able to give a very close offhand estimate of the entire work on such a house after a glance at the plans and specifications has assured him of the nature and number of fixtures. The estimator that is wise, however, is not usually ready to make a bona fide estimate on any system of plumbing without first going over the work very carefully, for it needs only a small difference here and there to make a considerable total difference. The practice of giving offhand final estimates is always to be condemned, as they may often lead to trouble later. Moreover, such estimates are unlikely to take into account any change in prices of material.

As already intimated, however, much benefit may be derived from reference to lists of stock and labor used on previous work of similar style and character to that which is to be estimated. This is especially true of such work as is to be found in the regulation line of dwellings, flats, and like buildings. The comparisons should not be made, by the way, without making due allowance for any change in prices that may have come about in the meantime.

Many plumbing systems, however, cannot be expected to be of a similar nature to other work previously constructed by the firm, in which case there is little benefit to be derived from a general comparison. Here experience and good judgment must be called into service.

The employer or estimator who is properly posted in his business will know how many feet of soil pipe of different sizes his workmen will be able to run in a day, how long he must allow for the roughing-in of each fixture under the methods followed by his men and under the ordinances of his city, and how long it will take to do the finishing work on each fixture. By thus figuring the work in detail the total should be arrived at with a sufficient amount of exactness.

In the matter of estimating labor, especially, there is no one who can do it so successfully as the man who is working at the trade and is fully acquainted with modern methods of construction.

If a systematic account is to be kept of all labor and material used on work, it is necessary to use some form of time card, from which an exact account of all labor and stock items may be obtained. Such a form is shown, in connection with this subject, below.

This form is very convenient, although some employers may prefer a different style.

The item of labor is given in detail on the front of the card, and stock used in connection with that particular job, No. 73, may be noted on the reverse side. The main part of the card is to be handed to the workman, while the stub is torn off at the perforated line and retained in the office until the card is turned in.

WM. GREENE & CO.

Given to .............................

.................................................................................

...............190

. .No: ,7.3

WM. GREENE & CO.

No. 73

Ordered by...........................

Ordered for...........................

Street and No..........................

Wants...............................

..................................................................

.............................................................

...........................................................................

..........................................................................

WORK COMMENCED.

Date.................. Hour........

COMPLETED.

Date.................. Hour........

............. Hour work .............

.........................

" " ......................................................

" " ..................................................

" " ......................................................

. . . .......... Hours contract .........

...............................

" ". ...............................................

" " .........................................