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SURVEYING BY BICYCLE.
TH 'HE newest use of the bicycle is as surveying machine. Not merely
a machine to carry a surveyor from point to point, but as a machine which performs in itself the mechanical part of the surveyor's work. The United States army is considering the advisability of adopting this machine as an adjunct to tactics. By means of an attachment the exact topographical characteristics of a road may be ascertained, with no other exertion on the part of the surveyor except a ride along the road in question. The rider may travel as fast as he likes or as slow as he likes, but when he has finished his trip, every gradient, hill or hollow, will have been accurately marked off on a strip of paper, which is part of the attachment in question. On the strip of paper the exact height of the hills and depth of the hollows were indicated. The mechanism is simple in the extreme; it can be attached to any wheel or other vehicle for the matter of that.
The importance of the invention in military practice can be easily appreciated. Hereafter a general contemplating a march can order his chief engineer to find out the exact topography of a road, over which the army is to pass. The engineer, taking his wheel, can ride ahead and return in a short time with an exact profile of the road, so that every obstacle in the way of heavy ordnance or supply waggons can be known and provided for long before the troops even start on their way. Or, while the army is on the march the engineer can ride ahead and leave his record at various stations along the road, his general thus being able to have placed before him, en route, the exact description of the road ahead of him.
Under orders from General Gobin, of the Third Brigade, Pennsylvania Militia, a survey of the road around Hazleton, Pa., connecting all the cainps and the strategic points was recently made. A method of rapid road sketching was adopted, and 49.22 miles were surveyed by means of a bicycle equipped with a cyclometer and a compass. It required 19 hours to do this alone, and the distances, and directions were then drawn out on paper. The elevations were all derived from barometric levels. This work occupied a great many hours, and yet the survey was so quickly made as to establish a new record for rapid work. With the new invention, the entire work could have been done in the time it would have taken a rapid bicyclist to cover the distance on his wheel.
It is also proposed that this invention be applied to mapmaking. The value of road maps would be considerably enhanced if all the grades could be shown as well as the distances. Bicyclists as well as waggon drivers would value highly a map of this character, inasmuch as it would tell them what work they or their horses would have to do.
The device is the invention of John Riddell, the mechanical expert of Schenectady, N.Y. It is simple enough. It consists primarily of two parts, a cylinder revolving mechanism to carry the strip of paper on which the record is made, and a device to make the record. The cylinder revolving mechanism is a slender; horizontal shaft. The cylinder is turned by means of a belt attached to the crank axle of the bicyele. As the cylinder turns the strip of paper is unrolled from a spool. The marker, hanging by means of a pivot and controlled by a complementary mechanism, adjusts itself to the position of the bicycle. When the bicycle runs down a hill, the marker moves toward the lower edge of the paper strip ; when the bicycle mounts a hill, the pointer travels toward the upper side of the paper. Naturally, the movements of the paper are in proportion to the size of the prominence or declivity along which the bicyclist is moving. It is, so to speak, the antithesis of the various picture enlarging apparatus or pantagraphs. The paper on which the record is made is marked off in para lel, horizontal lines. The scale is guaged so that every foot marked of on the paper represents 792 feet of road. The vertical scale is 400 to o e, so that if a hill shown on the paper strip is one inch high, the real hill of which the marking is a miniature picture, is 400 inches high. easy to calculate the distance and height of every grade passed over.
The Journal of the Institution of Surveyors, N. S. Wales
VOL. XIII. No. 2.
SYDNEY, FEBRUARY 24, 1900.
"Thx SURVEYOR,” which is published monthly, contains original articles on matters connected with Surveying, both of a technical and of a general character, extracts from Scientific journals on allied subjects, notes upon topics of professional interest, notices of appointments or changes in the personnel of the Government Surveying and Engineering Staffs, reports of the proceedings and transactions of the Scientific Institutions, and correspondence.
Literary matter may be sent to the Editors, 7. H. Loxton and John Miller, at the Office of the Institution, Queensland Offices, Bridge Street, Sydney.
Business communications should be addressed to the Business Manager, E C. Hughes, Queensland Ofices, Bridge Street, Sydney.
Items of News and Criticisms upon Contributed Articles appearing in our columns will be especially welcome.
T'he Editors do not hold themselves responsible for the opinions of correspondents, nor for the return of manuscript.
Gold DREDGING.–The Surveyor General of Queensland forwards us a copy of correspondence, from which we gather that the Executive Council of British New Guinea are engaged in drawing up an Ordinance and framing Regulations with regard to dredging for gold in that colony, and it would appear as if there would be an opening there for surveyors.
The following is extracted from a letter to the Surveyor-General, Brisbane, from Mr. H. H. Stuart Russell, Government Surveyor at Samarai, New Guinea (formerly a contract surveyor in Queensland), and ought to prove of interest to the profession generally :
"I may add that nearly every available yard of dredging waters' on the north-eastern coast of British New Guinea has been applied for, and that I am authorised to appoint such surveyors as I may
think fit, to effect those or any
may be required in the Possession. If, therefore, there are any competent licensed surveyors whose services are not at present in demand by the Queensland Governinent, and who would be prepared to undertake surveys here, I beg to state