A number of other articles and papers are listed in the Appendix. Many of these are of great value and are well worth careful perusal, but they offer no definite plan of valuation. Inasmuch as the general principles involved in the valuation of a water-works plant and a railroad plant are similar, it is advisable, in any exhaustive study of the subject, to review the articles descriptive of water-works valuation, and it is a matter of regret that greater consideration cannot be here given to some of the points raised by such engineers as George H. Benzenberg, Past-President, Am. Soc. C. E., Kenneth Allen, Arthur L. Adams, Emil Kuichling, Members, Am. Soc. C. E., and others in their various papers and discussions of this subject. The _Railway Age_, the _Railroad Gazette_, the _Railroad Age Gazette_, and the _Railway Age Gazette_ contain many editorials and articles on the valuation of railroad properties. These are written mainly from the standpoint of the railway official, and present many matters of interest which are worthy of study prior to undertaking a large appraisal. One series of articles in the _Railway Age Gazette_[13] is a most masterly argument, and it is to be regretted that the author has not disclosed his identity. The Michigan valuation has been discussed in two papers by Mr. Charles Hansel, whose connection with the work, as a member of the Board of Review, gave him probably a more intimate knowledge of it than any one else, not connected with the actual working organization, who has undertaken to review the work. His first paper, published in 1901,[14] entitled, "What is the Value of a Railroad for Purposes of Taxation?" is a discussion of the work of Professors Cooley and Adams, written while the subject was fresh in his mind. His second paper, an able argument for a Government valuation, appeared in the _North American Review_ in 1907. The one point to which special attention is drawn is Mr. Hansel's astonishing misconception of Professor Adams' plan of work. This misleading statement appears in the first paper and is reiterated in the second. It is of such a character that to pass it unchallenged would be doing great injustice to Professor Adams. He states Professor Adams' plan as follows: Capitalize net earnings and add to the present value of the physical appraisal as found by Professor Cooley. "The result would be that in case the present value per mile as determined by Professor Cooley is found to be $15,000, and the net earnings by Professor Adams are found to be $1,000, this capitalized at 5 per cent. would equal $20,000, and added to the present value would make $35,000, which would be the sum upon which taxes were to be levied. In other words, if the company actually earns $1,000 it increases its value for purposes of taxation 20 times that amount. If, however, instead of having a net earning of $1,000 it spends that sum in improving the property, it has only increased its taxable property by $1,000."