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26 feed water heaters, so that the whis- tles may be operated in from 12 to 15 minutes in place of 40 to 60, as now. The fog signal at Forty Mile Point will probably be discontinued as use- less and transferred to Portage river light station. "While this is a brief outline of past work and of our plans for the immedi- ate future, a few words of more gen- eral value should be added. "First in importance,.seems the mat- ter of the proper use of ranges. This question is of consequence in the Elev- enth district only in the St. Mary's river, especially below the canal, where the swift currents and narrow channels | make it desirable to use considerable care. So far as the Middle _Neebish and Little Mud Lake ranges are con- cerned, the early opening of the West. Neebish channel will greatly simplify - matters, as the up and down bound streams of navigation will then be sep- arated, but difficulties will still exist elsewhere, especially where opposing vessels insist on hugging the range. You know better than I how danger- ous and aggravating this practice is, ~and what disasters due 'to suction some-" times follow. It is, of course, possible to replace the ranges by buoys which are never at their stations at the be- ginning and close of the season when they are most neded; by double ranges, one for the up-bound, the other for the down-bound stream of traffic, but these would call for entire- ly new structures, and the purchase of much additional land, etc., finally chan- nel lights upon cribs could be used. It is safe to say that while congress has been very generous to lake interests, until it is proved that the single ranges now existing are absolutely inadequate, there will be very little chance of get- ting the large sums needed to pay for any one of the substitutes named. But when used with judgment and consid- eration for the rights of others, the ranges are not really inadequate. The proper and necessary way to use a range is to come on it squarely, and then knowing, either from the buoys, the chart, or from experience, how much the range may be opened, to open it to this extent as promptly as possible. The angle which measures the extent to which a range may be opened depends, of course, upon the .width of the channel and the distance from the range lights. I have caused a little table to be prepared showing the angles which a vessel's direction may make with the line of a few of the ranges, and for convenience the figures deduced apply largely to the Detroit river ranges, which are not in # & THe Marine REVIEW lf you will recall that a my district. 8 point is 11 deg. 15 tts and an eighth- point 1 deg. 24 ft, you will perceive that the angles with one exception, do not rise to a half point and are usual- ly much less than an eighth at the place where a vessel enters the range. A knowledge of these angles will then prove of little practical value. There- fore, the only way in which a range may safely be opened. is by experience based upon the proper use of the chart and the limiting channel buoys, and this is a matter that should constantly be borne in mind. If you believe that more buoys are needed to accomplish this result, it will be easy to supply them. oe "Wherever fixed lights now exist, especially in harbors. and near settle- ments, it would seem desirable to sub- "stitute flash lights for them. Do you desire such a change, and do you pre- fer the new style flash, as 'xemplified at Whitefish Point, to the old style as seen everywhere elSe-in the Eleventh district? A ee 2 "In the matter of day marks, is the new Style, consisting of nearly cylin- ~drical shell towers shown at Six Mile Point and Wind Mill Point, preferable to the -- old stalled targets? Finally, at present our fog signals usually give not to exceed two blasts per minute, and these are relatively long. Does this arrange- ment meet with your approval, and what is your opinion of the new com- pressed air siren, as exemplified at the Detroit river light station? Does it give as good service as the 10-inch steam whistle? "This concludes my remarks upon lighthouse matters, and as F. C. Shen- ehon, principal assistant engineer of the Lake Survey, is here to address you, I shall be very brief in speaking of the survey. "As you probably know, the lake survey was begun in 1841 and by 1852 the work was regarded as completed. During these years the total appropri- ations aggregated about $3,000,000. The result of this work, which was per- formed with great skill and accuracy, was a series of 76 lake and harbor charts, giving the limits of safe 12-ft. navigation. Unfortunately, while the size and draft of vessels continued to grow, the appropriations after 1882, and practically until 1900, were very. small, being - little more than the amount needed in publishing new editions of the old charts. By 1900, the need of charts, which should accurately show the limits for present day drafts, had become so pressing that appropriations upon a more liberal scale were re- colored glance the channel depths. Where the skeleton beacons with tion of the survey. ,average level happened tto be high, sumed, and since then the Lake Sun" vey has been fully occupied in revising and amplifying its charts, so that now we offer you 119 lake and _ harbor charts, practically all of them modern lithographs, showing at 2 old charts have been shown to be jn error, and these arrors are largely due to the fact that the old Lake Survey lacked certain appliances which are now in use, re-surveys have been made and corrected charts issued. Thus new surveys have been made in the Apos- tle islands, at the- west end of Isle Royale, at Grand Island, at the eagt end of Lake Superior, in the Straits of Mackinaw, in Green Bay, at the west end of Lake Erie, and at numerous harbors. In.addition much work has been done in connection with the meas- urement of lake outflow, largely with a view to preventing damage to navi- gation interests by diversions similar to the Chicago drainage canal, and also for the purpose of securing the infor- mation needed in the preparation of plans for regulating the levels of Laie Erie, Lake Huron and Lake Michigan. ©The old Lake Survey charts showed depths below a plane determined by the mean lake level during the dura- during subsequent low seasons, the charts would show depths greater than were then really available. This, of course, is not what you really need, and at present all our new charts show depths below a mean low water plane, which is lower than any stage which has ever occurred during the seasons of navigation. Thus, Lake Superior charts give depths below a plane whose elevation is 600.56 ft. above mean tide at Sandy Hook. For 47 years the level of Lake Superior between April and December has never been as low as 601, and its present level is over 2 ft. higher than our reference plane. So with Lakes Michigan and Huron, the level of the reference plane is 978.51, and the low water of 1895, the lowest 'on record, was half a _ foot higher than this. The November, 190/, level of these lakes was 580.79, also 2 ft. higher than the reference plane for these two lakes. On Lake Erie the -level of tthe reference plane is 569.91, and the present level is 572.37. The general and sectional charts of Lakes Superior, Huron and Erie, show these new reference planes, so that it is safe to say that during the season of navigation our charts always show less water than there actually is. This, you will probably agree, is a step in the right direction. If this mean or'