Van Nostrand's engineering magazine . given a firmbasis for the extension of the principleto a wider range. The importance of these two trials, asbearing on the practicability of aerialnavigation, cannot be denied; but doubtshave been expressed whether the resultsgiven can be implicitly accepted. It issaid (1) that the determination of the in-dependent speed must be so difficult asto be liable to error ; (2) that the resultsof the two trials, with such differentamounts of power, are very discordant,and (3) that had such marvelous ac-counts been credited at the time they VAN nostrands engineeri
Van Nostrand's engineering magazine . given a firmbasis for the extension of the principleto a wider range. The importance of these two trials, asbearing on the practicability of aerialnavigation, cannot be denied; but doubtshave been expressed whether the resultsgiven can be implicitly accepted. It issaid (1) that the determination of the in-dependent speed must be so difficult asto be liable to error ; (2) that the resultsof the two trials, with such differentamounts of power, are very discordant,and (3) that had such marvelous ac-counts been credited at the time they VAN nostrands engineering magazine. must have been followed up. In case, there is, it is true, only theunsupported statement of an engineer ofknown reputation and great skill; butwith regard to M. de Lomes trial, a ref- credible that the full detailed particularscommunicated to such a body as theFrench Academy, by a man of such , can have been otherwise thantrustworthy. The discrepancy between M. H. Giffards Dirigible Balloon, erence to the Comptes Kendus willshow abundant evidence of the correct-ness of his statements. He pre-arrangedwith great care the modes of observa-tion ; he was accompanied and assistedby several other persons, and it is in- the two trials will be explained else-where; and the apparent neglect of theexperiment is easily accounted for by thecircumstances of the time, and the wantof any sufficient inducement for its re-newal. The best answer, however, to THE PROBLEM OF AERIAL NAVIGATION. these objections is, that the results areperfectly consistent with mechanicalprinciples, as will now be shown. II. WHAT MAY BE DONE. Under this head it is proposed toinvestigate generally, as a mechanicalproblem, the capabilities of balloons foraerial navigation. Assuming that a suitable elongatedshape, of circular section, has been de-termined on, let the maximum diameterbe represented by <7, and the length byI. Then the contents will be pro-portional to d11 and
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Keywords: ., bookcentury1800, bookdecade1870, booksubjectenginee, bookyear1879
