In the case of a water-works inspection, so much of the value is included in the system of distribution mains, a form of property which is inaccessible, that much more dependence must be placed on a figure based on age; but there, also, as full investigation as possible should be made, in order to determine to what extent tuberculation or electrolysis has affected the pipes.
A general inspection (made in Minnesota by the appraiser with two assistants) would appear to be an excellent thing as a review of the whole work, but whether such an inspection would be sufficiently thorough to base thereon a set of final values, would appear to be doubtful.
The inspection in the field, in addition to the placing of a percentage for depreciation, should involve a complete check of the inventory, a correction of all errors, due to the construction of new property or the destruction or removal of old, and a compilation of all information required for a complete, correct, and intelligent appraisal of the physical property by the computing office. Every appraisal is different, and every property offers new problems and diverse conditions. These must be met, and therefore the field inspector must call particular attention to all matters specially affecting the values of the property he is inspecting.
It is impossible to anticipate all these conditions in advance, although the use of carefully prepared blanks and the standardizing of the form in which the data are gathered greatly simplify the work, not only in the office, but in the field.
III. The Computation.
On the completion of the field work, with all the preliminary data in the office, the computation must proceed, and with this part of the work there are many questions which must be taken up, considered, and definitely answered.
The classification and arrangement of the information as to the property to be valued, the costs and prices of the various materials entering into construction, the making and checking of such tables as may be required for estimating, the computing, checking, filing, indexing, and the various other routine details of work need not be referred to specially, as they must be worked out for each appraisal. The matters of principle that will be met are more important, and, while it would be impossible to mention all that may come up, it may not be amiss to refer to a few.
(a) In making an appraisal of several properties, to what extent shall these properties be grouped or classified?
(b) What unit prices shall be assigned in the estimates of cost of reproduction, and how shall they be determined?
(c) How shall right-of-way and real estate values be ascertained? Shall such elements as appreciation, or any increments due to the purpose for which the land is used, be treated as physical or non-physical values?