UNIVERSITY OF CALIFORNIA DEPARTMENT OF CIVIL. ENGINEERING BERKELEY. CALIFORNIA Library . - available po\ver is going oVer _ the top? Engineering Library W. & L. E. GURLEY Established 1845 TROY, N. Y., U. S. A. MANUFACTURERS OF Engineering and Surveying Instruments Transits Stadia Rods Levels Leather Cases Alidades Leather Pouches Plane Tables Hand Levels Sketching Cases Plummets Compasses Tripods Leveling Rods Chains Hydraulic Engineering Instruments Current Meters Water Stage Registers Printing Graphic Long Distance Hook Gages Precision Weights and Measures Standards of Mass, Capacity and Length, for Sealers and Manufacturers DEALERS IN Small Field Equipment and Accessories Drawing Instruments and Office Supplies Illustrated literature sent free upon request Conditions under which the Gurley Long Distance Recording Outfit is to operate By sending us the detailed information indicated below, you will enable us to advise you definitely regarding the best method of applying Gurley equipment to your local conditions. (I) Is the Sender to be placed on a: Power Reservoir ? Waterworks Reservoir ? River or Harbor ? ( 2) Will it be necessary to protect the water in the stilling well from freezing ? ( 3) What is the ordinary range of water level to be recorded ? ( 4) What is the maximum range ? How many times a year may it be expected ? ( 5) What is the line distance from the Sender to the Recorder ? If two or more Recorders are to be used, give the distance from Sender to each, and between them. , ( 6) Is there a line available ? 2 or 3 wires ? ( 7) What kind and size of wire is it ? ( 8) Are there telephones on this line ? . If so, how many ? Are they grounded ? Are they connected to any telephone switchboard ? (9) If a new line is to be built, what size and kind of wire will be used ? Will 2 or 3 wires be put up ? (three are more reliable.) ( 1 0) Will telephones be used on the new line ? How many ? (II) Will the instrument be operated by: 1 1 Volts D. C. ? Storage batteries ? Dry batteries ? Signed 'Title Company Address City State Mail to W. & L. E. Gurley, Troy, N. Y. HYDRAULIC ENGINEERING INSTRUMENTS Cost of Gurley Long Distance Recording Equipment The cost of installing the Gurley Long Distance Recorder depends very largely on local conditions and our Engineering Department will gladly co- operate in suggesting how local problems may best be solved. The prices of Sending and Recording apparatus are as follows: No. 638-A Long Distance Recording Outfit, consisting of a No. 638 Sender and a No. 637 Recorder $385.00 No. 638-B Long Distance Indicating Outfit, consisting of a No. 638 Sender and a No. 639 Indicator 265.00 No. 638-C Long Distance Recording and Indicating Outfit, consisting of a No. 638 Sender, a No. 637 Recorder, and a No. 639 Indicator 540 . 00 Separate instruments may be had for the following prices: No. 637 Recorder, complete with glass cover, 10 extra record sheets, 1 bottle of clock oil. Shipping weight about 100 Ibs. 275.00 No. 638 Sender, complete with metal cover, one lock, one 20 inch float, 1 counterweight, 20 ft. phosphor bronze tape, 2 guide pulleys, 1 bottle of clock oil. Shipping weight about 75 Ibs. 110-00 No. 639 Indicator, complete with glass cover, and 1 bottle of clock oil. Shipping weight about 1 5 Ibs. /T 155.00 Prices are F. O. B. Troy, N. Y. Installation Instructions Detailed instructions for the proper installation of the Gurley Long Distance Recording Outfit will be sent upon request. Manual of Gurley Hydraulic Engineering Instruments This beautifully illustrated book of 1 60 pages describes in detail the con- struction of our Current Meters, Hook Gage and Water Stage Registers. In addition it contains a great amount of useful information relating to the use and care of the Current Meter and the Hook Gage, and also concerning the installation and operation of Water Stage Registers. The illustrations have been selected to show the various kinds of current meter rating and gaging stations and the different methods of making current meter measurements under various conditions. Also, to indicate the different types of installations and shelters for Water Stage Registers and the many appli- cations to which Gurley Meters and Registers are adapted in connection with sewers and sewage disposal plants, irrigation, drainage, water supply and hydro- electric developments, stream gaging, harbor investigation and similar projects. A copy of this Manual is furnished free to purchasers of our Current Meters and Water Stage Registers. To others it will be supplied for the nominal price of seventy-five cents per copy. 11 Gurley Current Meters "Standard of the World" Used everywhere by Government and private hydraulic engineers for accur- ate stream flow measurements. No. 623 Universal Pattern, indicating each revolution ; or each fifth revolu- tion ; and suspended by cable, or by jointed wading rods. Principal Advantages: Reliability in action Simplicity of design Rigidity of construction Adaptability Convenient size W. & L. E. GURLEY Established 1845 TROY, N. Y., U. S. A. H-305 PANAMA-PACIFIC INTERNATIONAL EXPOSITION GRAND PRIZE Certificate and GOLD MEDAL awarded W. & L. E. Gurley for Hydraulic Engineering Instruments at the Panama - Pacific International Exposition, San Francisco, 1915. Manual of Gurley Hydraulic Engineering Instruments Second Edition Price, 75 Cents UNIVERSITY OF CALIFORNIA DEPARTMENT OF CIVIL ENGINEERING BERKELEY. CALIFORNIA W. & L. E. GURLEY, Makers Established 1845 TROY, N. Y., U. S. A. COPYRIGHT, 1921 BY W. & L. E. GURLEY TROY, N. Y., U. S. A. Foreword THE importance of an exact knowledge concerning the sur- face water supply of the country has been recognized for many years. The immediate necessity for stream flow data, to be used by those interested in or engaged upon problems of hydraulic engineering, including water power, domestic water supply, sewage disposal, inland navigation, irrigation, swamp and overflow land damage and flood prevention, has created a constantly increasing demand for accurate stream flow measurements. The relative importance of the different uses of the surface water supply of the country varies, not only in different local- ities, but also from time to time in the same section as industrial conditions change. These uses all require accurate quantitative estimates for their successful application. Without question the relation of stream flow records to the economic development of the country is one of continually increasing interest. The desirability of investigating its water resources, one of the most valuable natural assets that a country possesses, cannot be too strongly emphasized. Considering these facts and also the many costly experiences resulting from misinformation, it is apparent that all data must be collected with appropriate equipment, including properly designed and well constructed instruments, in order to be accurate and dependable. Inasmuch as it is usually impossible to predict future uses of stream flow data at the time the records are made, in many cases most urgent demands for depend- able long time records are made when it is impossible to produce them, all stream gaging work should progress toward the collection of continuous records of the highest standard of 8 W. & L. E. GURLEY, TROY, NEW YORK accuracy. The energies of some of the foremost engineers of the world have been given to this work, and as a result both methods and appliances have been highly perfected. For many years W. & L. E. Gurley have been the leaders in the manufacture of instruments for the measurement of water. At the Panama - Pacific International Exposition they were given the highest award for Hydraulic Engineering Instruments. Every part of these instruments is constructed from carefully selected material, and is accurately made and finely finished by experienced workmen in the Gurley Factory, which has been producing precision instruments and equipment for over seventy-five years. They consist of Engineering and Surveying Instruments, such as Transits, Levels, Compasses, Plane Tables, Alidades, Sketching Cases, Leveling Rods and Stadia Rods; and Standard Precision Weights and Measures. The methods commonly used in carrying on water measure- ments are described in standard text books, to which frequent reference has been made in preparing this Manual. We are indebted to prominent hydraulic engineers for suggestions and photographs, and grateful acknowledgment is hereby made to these friends for their co-operation, as well as to the authors quoted in this book. W. & L. E. GURLEY Contents PAGE c FOKEWORD 7 PART I. GURLEY CURRENT METERS Their Construction, Care and Use 13 INTRODUCTION 13 DESCRIPTION OF GURLEY CURRENT METER AND EQUIPMENT 14 1. The Head 14 2. The Tail 17 3. The Hanger and Weights 17 4. The Recording or Indicating Device 18 5. The Suspending Device - 19 SELECTING THE PROPER TYPE OF CURRENT METER 21 ADVANTAGES OF GURLEY CURRENT METERS 28 COMPLETE CURRENT METER FIELD OUTFIT 29 TIME RECORDER OR STOP WATCH 30 CARE OF THE CURRENT METER 31 To take the Meter apart 31 To change Contact Chambers 31 Special Instructions 32 RATING THE CURRENT METER 34 TYPES OF CURRENT METER MEASUREMENTS 39 Wading Measurements 42 Measurements from Cables 44 Measurements from Bridges 47 USE OF THE CURRENT METER 48 Soundings 48 Velocity Observations 49 Recording the Data 52 Low Water Measurements 59 Measurements under Ice 59 Measurements in Artificial Channels 62 ACCURACY AND RELIABILITY OF THE CURRENT METER 62 SELECTION AND LOCATION OF GAGING STATIONS 63 Reconnoissance 63 Observers 70 Establishment of Stations 70 GAGES 71 Non-Recording Gages 71 Gurley Hook Gage 73 Recording Water Stage Registers 75 BENCH MARKS 75 PART II. GURLEY AUTOMATIC WATER STAGE REGISTERS Their Con- strutcion, Installation and Operation 77 INTRODUCTION 77 CONDITIONS REQUIRING THE USE OF AUTOMATIC WATER STAGE REGISTERS 78 1. W T here water is valuable and exceptionally accurate records are necessary. 78 2. Where artificial or natural stream conditions cause sudden changes in stage in 24 hours. 78 3. Where records are desired on a flood-water stream which is dry most of the year. 79 4. Where complete records are desired on a stream which flows continuously but is subject to sudden floods. 79 5. Where it is necessary to determine the maximum gage height or the maximum daily mean gage height. 80 6. Where it is necessary to determine the minimum gage height or the minimum daily mean gage height. 80 CONTENTS PAGE 7. Where small streams of sudden fluctuation are measured by weirs for adjudication of water by the courts. 81 8. Where available gage readers do not have sufficient intelli- gence to read a gage, or cannot be trusted. 81 9. Where the station is situated at an isolated point and a gage reader is not available. 81 ESSENTIAL FEATURES OF AUTOMATIC WATER STAGE REGISTERS 81 The Float 82 The Transfer Mechanism 84 The Record Sheets 85 The Clock 85 The Cover 86 TYPES OF GURLEY AUTOMATIC WATER STAGE REGISTERS 86 Gurley Printing Water Stage Register 87 Advantages 87 Construction 91 Installation and Operation 97 Gurley Graphic Water Stage Register 10 foot Range 102 Advantages 102 Construction 104 Installation and Operation 108 Instructions for Changing the Range of Nos. 633 and 636 Graphic Water Stage Registers 110 Gurley Graphic Water Stage Register 1 foot Range 111 Advantages 113 Construction 113 Installation and Operation 114 Gurley Long Distance Graphic Water Stage Register 119 Type of Record 120 Simplicity of the Outfit 120 The Long Distance Sender 121 The Long Distance Register 122 The Construction of No. 637 Long Distance Register 123 The Long Distance Indicator 124 Electrical Circuit for the Long Distance Outfit 125 Installation and Operation of the Gurley Long Distance Outfit 127 Gurley Indicating Gage 130 INSTALLATION AND SHELTER FOR WATER STAGE REGISTERS 131 CARE AND COMPUTATION OF RECORDS 136 OTHER APPLICATIONS OF GURLEY CURRENT METERS AND WATER STAGE REGISTERS 142 Measurements of Sewage 142 Soundings and Tide Gages 144 Navagation Canals 144 Irrigation Canals 146 Hydraulic Power Stations 146 Flumes 148 Weirs . 148 SUGGESTIONS FOR THE SELECTION OF AUTOMATIC WATER STAGE REGISTERS 150 Printing Register 150 Graphic Registers 151 LEVELING INSTRUMENT AND ROD 154 Gurley Explorers Level 154 Gurley Leveling Rod 15'5 INDEX 156 PRICE LIST _. _ IN COVER POCKET Illustrations PAGE GRAND PRIZE CERTIFICATE AND GOLD MEDAL FRONTISPIECE F IG< i. Gurley Current Meter and Attachments 15 2. Reel for use with Current Meter 20 3. NO. 616 Acoustic Current Meter Outfit 22 4. No. 623 Electric Current Meter Outfit, with meter suspended by cable 23 5. No. 623 Electric Current Meter Outfit, with meter suspend- ed by jointed wading rods 23 6. .Nos. 617, 621 or 623, attached by a double end hanger to a flush-jointed wading rod 24 7. No. 609 Electric Register 25 8. Special Fibre Carrying Case for Current Meters, 26 9. Testing Meter Circuit 33 10. Testing Meter Circuit 33 11. Testing Meter Circuit 33 12. Current Meter Rating Station at U. S. Bureau of Standards 34 13. Current Meter Rating Station of Irrigation Branch Canadian Interior Department 35 14. Boat equipped for Current Meter Measurements 39 15. Catamaran equipped for Current Meter Measurements 39 16. Natural Control of a Stream 41 17. Artificial Control of a Stream 41 18. Wading Measurement 43 19. Typical Gaging Station for Wading Measurement 43 20. Current Meter Gaging Station 44 21. Typical Current Meter Gaging Station with Automatic Water Stage Register 45 22. Current Meter Observers in Cable Car __: 45 23. Russian Government Engineers using Gurley Current Meters in Turkestan 46 24. Typical Gaging Station for Bridge Measurement _ 47 25. Form No. H-325, Discharge Measurement, General Data 54 26. Form No. H-326, Current Meter Notes 55 27. Cross-section of Stream to Illustrate Discharge Measurement Computation 56 28. Winter Measurement 57 29. Current Meter Measurements in Winter 58 30. Current Meter Measurements in Winter 58 31. Current Meter Measurements in Winter 58 32. Diagram Indicating Notation used in making Discharge Measurements under Ice, with Form for Notes 60 33. i c e Chisel, Ice Measuring Stick, and Bag _ 34. Winter Measurement 61 3.5. Showing poor location of Gaging Station 66 36. Showing proper and improper location of Gaging Station 67 37. Showing poor location of Gaging Station : 68 38. Vertical and Inclined Staff Gages 72 39. No. 628 Hook Gage 73 40. United States Geological Survey Bench Mark 76 41. Section of Paper Tape, showing Printed Record made on a No. 630 Printing Register 87 42. No. 630 Printing Water Stage Register, Front View 88 43. No. 630 Printing Water Stage Register, Side View 90 44. No. 632 Tape Reel, for use with No. 630 Printing Register __ 91 45. No. 630 Printing Water Stage Register 92 46. No. 630 Printing Water Stage 'Register 94 ILLUSTRATIONS PAGE Fio.47. Details of Installation of No. 630 Printing Register 90 48. No. 633 Gurley Graphic Water Stage Register, with Spring- driven Clock 105 49. Diagram of No. 633 Gurley Graphic Register 106 50. No. 636 Gurley Graphic Water Stage Register, with Weight- driven Clock 107 51. Showing method of inserting ends of the Record Sheet in the slot in the Cylinder 109 52. No. 634 Gurley Graphic Water Stage Register 112 53. Diagram of No. 634 Gurley Graphic Register 114 54. Record Sheet for No. 633 or No. 636 Graphic Register 117 55. Record Sheet for No. 634 Graphic Register 118 56. No. 638 Float Operated Sender, for Long Distance Graphic Register 121 57. No. 637 Long Distance Graphic Water Stage Register 122 58. No. 637 Long Distance Register 123 59. No. 639 Indicator, front and rear views 124 60. Wiring Diagram showing the method generally used in installing Gurley Long Distance Registers 125 61. Wiring Diagram of the installation of a Gurley Long Distance Register at Topeka, Kansas : 126 62. Diagram showing location of holes in table and floor of Gage House for Long Distance Register 127 63. Details of installation of a No. 638 Long Distance Sender 128 64. No. 639-A Indicating Gage 130 65. Portable Shelter installed by U. S. Geological Survey on Kinderhook Creek at Rossman, N. Y. 131 66. Device for reducing quantity of oil used as a cover in wells _ 134 67. Reinforced Concrete Well and Shelter installed by U. S. Geological Survey on the American River at Fairbanks, Cal. 135 68. Concrete Shelter containing a Gurley Printing Register, as in- stalled by the U. S. Geological Survey on the Genesee River at St. Helena, N. Y. 135 69. Metal Shelter and Well 137 70. Metal Shelter with door open 137 71. Wooden Well and Shelter 138 72. Water Stage Register installation in California 138 73. Wooden Well and Shelter installed at a Bridge Abutment 139 74. Wooden Well and Shelter installed against a Bridge Pier __ 139 75. U. S. Geological Survey Form for Inspection of Recording Register Stations 140 76. Installation of a Graphic Register in manhole of a sewer 142 77. Installation of a Graphic Register on New York State Barge Canal 145 78. Installation of a Graphic Register on New York State Barge Canal 145 79. Installation of a Graphic Register on New York State Barge Canal 145 80. Installations of Printing and Graphic Registers in connection with the Keokuk Dam 147 81. Installation of a Register at a Weir 148 82. Gurley Experimental Gaging Station, Troy, N. Y. 353 83. No. 384 Explorers Level 154 84. No. 524-A Plain Leveling Rod, 4-Ply 155 Manual ; , " of Gurley Hydraulic Engineering Instruments PART I. GURLEY CURRENT METERS (PRICE PATENTS) THEIR CONSTRUCTION, CARE AND USE* INTRODUCTION FOR more than thirty years W. & L. E. Gurley have made Current Meters under the patents of W. G. Price, the Assistant Engineer of the Corps of Engineers, Unites States Army, who in 1885 devised the initial pattern. The general features are retained in the latest models, although somewhat modified as the result of suggestions from many hydraulic engineers who have had large experience in current meter observation under all conditions of service. The many hundreds of Gurley Current Meters in use in all parts of the world, their constantly increasing sale and their accuracy and reliability under all conditions, show that they are the standard instruments for the accurate measurement of the velocity of water in streams and open conduits. A current meter for measuring the velocity of flowing water comprises two essential parts: (a) a wheel arranged so that when suspended in flowing water the pressure of the water against it causes it to revolve; (b) a device for recording or indicating the number of revolutions of this wheel. The rela- tion between the velocity of the moving water and the revolutions of the wheel is determined by rating each meter. "Largely quoted from " The use and care of the current meter, as practised by the U. S. Geological Survey," by John C. Hoyt, Trans. Am. Soc. C. E., volume 66, page 70, 1910. " River Discharge," by Hoyt & Grover, for sale by W. & L. E. Gurley, price $2.50 postpaid, gives a complete treatise of the methods of collecting and analyzing stream-flow data. In the preparation of this Manual this book has been largely used and many direct quotations are made from it. i4 ; . w. #.L: s: GURLEY, TROY, NEW YORK ;'-'-, \ s FKe distinguishing characteristics of a good current meter are (a) simplicity in construction, with no delicate parts which easily get out of order; (b) a small area of resistance to the velocity of the water; (c) a simple and effective device for in- dicating the number of revolutions of the wheel; and (d) easy adaptability to use under all conditions. DESCRIPTION OF THE GURLEY CURRENT METER AND EQUIPMENT The small Gurley Current Meter and equipment consist of five principal parts: (1) the head; (2) the tail; (3) the hanger and weights; (4) the recording or indicating device; and (5) the suspending device. In the following descriptions the numbers in parentheses refer to Fig. 1. 1. THE HEAD. The head consists of a ID - shaped yoke (1) carrying a wheel made of six conical cups (2), attached to a horizontal frame (3). This wheel, referred to as the cups, turns in a counter clockwise direction on a vertical axis known as the cup shaft, which rests and revolves on a pivot point bearing at the lower end and engages the recording mechanism at the upper end. The Cup Shaft consists of two parts (4, 5) clamping the cup frame. They are screwed together from either side of the frame, thus fastening the cups rigidly and at right angles to the cup shaft. At the lower part of the cup shaft there is a bucket nut having a pivot bearing which receives the pivot point (6) on which the cups revolve. The Pivot Point is screwed through a metal bushing (7) known as the frame nut, and is firmly held by a lock-nut (8). The frame nut slides into the lower arm of the yoke, and is clamped in position by a set-screw. By means of a raising nut (9) on the lower part of the shaft, the cups should always be lifted from the pivot point when the meter is not in use. This raising nut has a left-hand thread, so that it will not tighten when the cups revolve when in use. The upper part of the cup shaft is fitted with either a worm gear or an eccentric that passes into a cylindrical chamber (10), CURRENT METERS 15 Scale, in inches 0123456 FIG. 1 Gurley Current Meter and Attachments. UNIVERSITY OF CALIFORNIA .c.FARTN.ENT OF CIVIL ENGINEER! rrRKELEY, CALIFORNIA 16 W. & L. E. GURLEY, TROY, NEW YORK known as the contact chamber. This chamber contains the mechanism for making the contact which indicates the revolu- tions of the cups. The construction and arrangement of both the contact chamber and the mechanism contained in it depend on whether the indicating device is penta-count electric, single-count electric, or acoustic. When the penta-count electric indicating device is used, the contact chamber (10) which is closed by a screw cap (11), provided with a leather gasket for keeping out the water, is held by a sliding fit in the upper end of the yoke, and is clamped in position by a set-screw. In the contact chamber there is fitted a cylindrical plug (12) which is held in position by a screw and carries a gear-wheel (13). This engages the worm gear on the upper end of the cup shaft, the gearing being so arranged that the wheel makes one revolution for every twenty revolutions of the cups. On the side of the wheel are four pins, equally spaced and set so that they will strike the contact spring (14) at each fifth revolution of the cups, thus closing the elec- tric circuit to the indicating device, explained later. These contact parts are known as the contact wheel, the contact pins, and the contact spring. The contact spring is carried by the contact plug (15) which is screwed into the contact chamber through a hard-rubber bushing (16) that insulates the contact spring from all other parts of the meter when it is not touching one of the pins on the contact wheel. In the outer end of the contact plug there is a hole and a set-screw for connecting one wire from the indicating device. When the single-count electric indicating device is used, the contact chamber (lOa) and appurtenances are the same as described for the penta-count contact chamber, with the excep- tion that the gear wheel (13) is omitted and the worm gear on the upper part of the shaft (4) is replaced by the eccentric (4a) that strikes the contact spring (14a) at each revolution, thus closing the electric circuit to the indicating device. The penta- and single-count contact chambers are interchangeable. The electric indicating device is used when the meter is suspended from a meter cord attached to the stem (23), or is held by a rod either screwed into the coupling (57), or sliding through the connection (54). CURRENT METERS 17 When the acoustic indicating device is used, the contact chamber (lOb) is closed with a cap (lib) fitted with a metal drum (49), and, in place of the contact spring (14) and plug (16), there is a small hammer (50) which is caused by the pins on the side of the gear-wheel (13a) to strike the drum at each tenth revolution of the cups. In order to keep the water from deadening the sound by rising into the contact chamber (lOb), it is raised about four inches above the yoke (la) by inserting the tube (59) and lengthening the upper part of the shaft (4a). The acoustic meter is always supported on a rod (51) attached to the contact chamber. 2. THE TAIL. The tail is used when the meter is suspended by a cable, or on a sliding hanger rod. It balances the head, and also keeps the axis of the meter parallel to the direction of the current. It consists of a stem (17) which is held by a sliding fit into a socket in the stem of the yoke, in which it is clamped by a set-screw. On this stem there are two vanes (18 and 19) set at right angles. One of the vanes is rigidly attached to the stem; the other fits into grooves on the first and may be pulled out readily when the key (20) that holds it in place is turned. On one of the vanes there is a slot carrying a weight (21) that can be adjusted to balance the meter. 3. THE HANGER AND WEIGHTS. When suspended by a cable, the meter is hung by a screw-bo] t (22) on a steel stem (23) that passes through a slot in the stem of the yoke. The slot in the stem of the yoke is wide enough to allow the meter to swing freely in a vertical plane, and the bolt passes through the frame a little above the center of gravity of the meter, so that the latter will readily adjust itself to a horizontal position. In the upper end of the hanger there is a hole for attaching the suspended cable, and at intervals along the stem there are other holes by which the meter and lead weights may be hung. The weights (24) are of torpedo shape, a design which offers the least resistance to the current, and are made in two sizes weighing, respectively, 10 and 15 pounds. They are attached to the stem by a screw bolt. The order in which the weights and meter are placed on the stem, depends on the conditions under which the measurements are to be made. When the meter is used on a rod, the hanger, the weights, and sometimes the tail are dispensed with. 18 W. & L. E. GURLEY, TROY, NEW YORK The set-screws for clamping the various sliding fits are all of the same size and are of standard make. Beveled grooves are provided in each of these connections, so that when the set- screws engage them the parts are drawn into place. All parts of the meter are standard, and can readily be replaced in the field. Parts should always be ordered by Shop Number from the illustrations in the Price List. 4. THE RECORDING OR INDICATING DEVICE. A recording or indicating device is necessary for determining the number of revolutions of the meter wheel, and the successful use of the meter depends largely on this part of the apparatus. Various devices, operated either on the mechanical, electric, or acoustic principle, have been used for this purpose. These include the telegraph ticker, automatic recorder, electric buzzer, telephone receiver, drums, etc. Of these, however, the telephone receiver and the acoustic indicator have been found to be most satisfac- tory in general practice. The telephone attachment consists of a telephone receiver (25) and small battery (26) placed in a partial circuit which terminates in a connecting plug (27) by means of which the apparatus can be readily connected in circuit with the meter. The magnets of the telephone receiver are wound so as to secure a loud click. The dry battery (26) is compact and can be replaced read- ily. It is equipped with binding posts to receive the two wires. In use, the telephone receiver is fastened on the shoulder by a large safety pin, or is held at the ear by an operator's head band, which is worn under the cap, if preferred. The battery cell is placed in the coat or trousers pocket. The connecting plug (27) should hang below the shoulders and be easily acces- sible for attaching and detaching the meter circuit. In the acoustic indicator, the striking of the hammer (50) on the drum (49) in the contact chamber (lOb) indicates each tenth revolution of the meter, as already explained. The sound is transmitted through the rods (51) and a rubber tube to the ear of the operator. The rubber end and ear-piece are not necessary unless there is considerable noise. ^ CURRENT METERS 19 Audible indicators, such as the telephone and the acoustic signalling device, have the advantage of enabling the operator to detect any irregularities caused by trouble with the meter, battery, electric circuit, or any part of the equipment. A stop- watch is necessary for the proper observation of time. Electric recording devices are sometimes used, particularly when measuring the discharge of large navigable streams. For this purpose specially designed boats manned by several assistants are used. 5. THE SUSPENDING DEVICE. The suspending device, which consists of a rod or of some form of cable, must provide for lowering the meter and weight into the water and also for com- pleting an electric circuit which includes the contact chamber, the meter, and the recording device. The rod in common use in connection with the electric recorder consists of a /^ inch tube (55) graduated to feet and tenths. For convenience in carrying, it is made in 1.5 or 2 foot sections fitted with screw threads, the 2 foot section being standard. The sections of the rod are connected by flush joints which offer no obstruction to the movement of the sliding hanger. Two methods of hanging the meter on the rod are in use. By the first the head and tail of the meter are attached to a sliding hanger (54), which can be moved up and down the rod or clamped in any position. On the bottom of the rod there is a flat base (53) which keeps it from sinking into the bed of the stream, and at the top there is a plug (56) for connecting one of the wires from the recording device. The circuit between the meter cups and the recording device is made by attaching one of the wires from the recording device to the plug in the top of the rod. The other wire follows down the rod and is attached to the contact plug of the meter. In the second method the rod (58) is connected by the screw socket (57) in the yoke. The rods (51) for use with either type of meter are of /^ inch tubing graduated to feet and tenths and, for convenience in carrying, are made in 1.5 or 2 foot sections which screw together. The bottom rod connects with the contact chamber (49) by a screw, and is cut so that the zero reading is the plane 20 W. & L. E. GURLEY, TROY, NEW YORK of the center of the cups. On the upper end of the top rod there is a flat plate (52) in the center of which there is a hole through which the sound from the drum can be heard. The soundings are made with this end of the rod. and the plate keeps the end from sinking into the bed of the stream. The meter cables must be strong enough to support the weight required to hold the meter in place while making obser- vations, must be water-proof to avoid short circuits and must be tough and flexible to withstand hard usage. They should be as small in diameter, consistent with strength, as is possible, in order to offer small resistance to the water. They may be graduated in feet by means of markers, for convenience in measuring depths. Greater precision in such measurements is obtained by using a single index point and applying it to a fixed scale. This method eliminates the effect of any possible stretch in the cable. When used on a cable reel, (See Fig. 2) the scale and index are part of the reel. Reels should be used at any place where a considerable number of measurements are to be made, both as a matter of convenience in handling the equipment and to protect the elec- tric circuits in the meter cable from the effects of twisting and abrasion. FIG. 2 Reel for use with Gurley Current Meter. Designed for use on a railroad bridge having a narrow foot walk. The reel is fastened on the side opposite the meter, so as to prevent it from tipping. CURRENT METERS 21 SELECTING THE PROPER TYPE OF CURRENT METER The experience of many years has shown that only two patterns of the Gurley meter are needed to adequately meet the requiremnts of practically all engineers engaged in measur- the flow of water, namely the Acoustic type, No. 616, and the Electric type, represented by Nos. 617, 621 and 623. Accordingly, the large model formerly listed as No. 600, and one of the smaller patterns, No. 618, have been discontinued. No. 617 and No. 621 have been standardized by equipping them with the Covert yoke, as described on page 24, thus mak- ing them correspond to No. 623 except that only one commuta- tor box is supplied, single count with No. 617, and penta count with No. 621, whereas No. 623 has both of these features. Thus, if Meter No. 617 or No. 621 is selected and the engineer finds that both commutator boxes are required, he can purchase the extra single count or penta count head and then have Meter No. 623. The selection of a meter should be made after consideration has been given to the following factors: (1) The purpose for which the instrument is to be used. (2) The manner in which it is supported. (3) The amount of weight to be used. (4) The frequency of the revolutions to be indicated. When it is possible for the observer to approach the stream closely, and to hold the meter in position by means of its suspen- sion rod, especially in channels of small depth, the Acoustic Current Meter No. 616 is very useful. This meter indicates each tenth revolution. See page 22. No. 616, the Acoustic Current Meter, is so called because the revolutions of the bucket wheel are indicated by the sound of a hammer striking against a diaphragm, one blow for every 10 revolutions. The indicating mechanism is completely enclosed and thoroughly protected from injury. When in use the meter is held by a sleeve-jointed wading rod, which screws into the frame and in connection with a rubber tube and ear piece attached to it, forms a passage through which the sound 22 W. & L. E. GURLEY, TROY, NEW YORK of the hammer stroke is transmitted to the ear of the observer. This enables him to count the number of revolutions of the wheel in any given space of time, and then by means of the rating table to ascertain the velocity of flow. Many observers perfer an electric type of revolution in- dicator. In some cases it is desirable to have more than one person hear and bear witness to the number of revolutions. For this purpose an electric indicator is preferable. To meet these demands, Electric Meters Nos. 617, 621 and 623 are offered. FIG. 3. No. 616 Acoustic Current Meter Outfit, with sleeve-jointed wading rods, rubber tube, ear piece- and connection. Indicating each tenth revolution. In all of these patterns, the indicating device is protected from injury by enclosure in the contact chambers, or commutator boxes, and the revolutions of the bucket wheel are indicated by a telephone receiver, which is generally fastened in a con- venient position on the observer's coat. These meters are suspended in use by a wire or cable attached to the steel weight hanger which, after passing through CURRENT METERS 23 the frame, suspends the torpedo-shaped weight necessary to hold the meter in the vertical plane against the current. The vanes on the weight assist in keeping the meter parallel with the direction of the current. The number and position of the weights on the stem or hanger depend upon the conditions under which the measurement is to be made. A tail, consisting of a stem to which are fastened two vanes (separable in packing), is attached to the frame opposite the bucket wheel and serves the double purpose of balancing the bucket wheel and keeping the meter parallel to the direction of the current. FIG. 4. No. 623 Electric Current Meter Outfit, with meter suspended ~by cable, and with telephone sounder, cable, dry cell battery, and two commutator boxes. Indicating each, or each fifth, revolution. FIG. 5. No.623 Electric Current Meter Outfite, with meter suspended by jointed wading rods, and with telephone sounder, cable, dry cell battery, and two com- mutator boxes, Indicating each, or each fifth, revolution. All of the advantages of Meters No. 617, 618 and 621 are combined in No. 623, which can be suspended by cable or by jointed wading rod, and which is equipped with two inter- changeable commutator boxes for indicating each revolution, or each fifth revolution, of the bucket wheel. 24 W. & L. E. GURLEY, TROY, NEW YORK The combination of these features provides an outfit which has been adopted as standard by the most efficidnt hydraulic engineers. This meter is used extensively by the Water Re- sources Branch of the United States Geological Survey, the leading organization devoted to the precise measurement of water The contact chambers (Commutator boxes) may be readily interchanged, the only change being in the shaft and consisting of the insertion of a cam on the end of the bucket shaft when a single revolution is to be indicated, or the insertion of a worm when it is desired to indicate every fifth revolution. A screw socket is provided on the frame of Meters Nos. 617, 621 and 623,, to receive a series of graduated rods by which any of these meters may be suspended, if desired, in- Fio. 6. Meters Nos. 617, 621 or 623, attached by a double-end hanger to a flush-jointed wading rod, having a removable base. stead of a cable, no change being made in the meter except the removal of the weight hanger. This device is known as the Covert Yoke, after its designer, Mr. C. C. Covert, of the United States Geological Survey. The removable base for the flush- jointed wading rods used in connection with a double-end hanger, serves to prevent the meter from sinking into the bed of the stream. CURRENT METERS 25 The flush-jointed rods will also fit the Covert Yoke of Meters Nos. 617, 621 and 623, and can thus be used for suspending the meter in the manner illustrated in Fig. 6. The present type of dry battery is suitable for carrying conveniently in the coat or shirt pocket and can be replaced at most electrical supply stores. When this size is not obtainable, the use of any standard six inch dry cell is recommended. The improved form of connecting block between the cable and telephone receiver has a locking device which prevents the two sections from becoming disconnected accidentally. A time recorder or stop watch of fine quality will be found desirable in observing the revolutions of the bucket wheel for any given time. No. 619 is recommended. (See Price List.) FIG. 7. No. 609 Electric Register. Whenever it is desirable to record the revolutions of the bucket wheel of Meters Nos. 617, 621 and 623, an Electric Register may be substituted for the telephone receiver ordi- narily used. Electric Register No. 609 has been developed recently and is a great improvement over the former pattern. It is suitable for use with current meters or any other intermittent contact device of which a record is desired. This device consists of a three figure "Veeder" counter operated by an electro-magnet and springs, and is so arranged that the same force acts on the counter regardless of how much 26 W. & L. E. GURLEY, TROY, NEW YORK current is used. This results in a uniform action and guar- antees against any skipping or missing, under widely varying conditions. This instrument will operate under favorable conditions with one good dry cell, but should have two, as a protection against deterioration of the battery. It requires but 0.31 ampere with two cells, which is a much smaller current than was necessary with the old style register, and which will not burn the current meter contacts. There are no dials to read, the total result being shown directly by the figures, so that there is small chance of an error in reading. FIG. 8. Special Fibre Carrying Case for Current Meters. All current meters are packed in a wooden box with lock, hooks and carrying strap, and including accessories of oil can, wrench, screwdriver and extra pivot bearing. A special carrying case of fibre, having two compartments, one for the meter and the other for the lead weight, cable, sounder, etc., as shown in Fig. 8, can be furnished at an additional price, for Meters No. 617, 621 or 623. CURRENT METERS 27 Meters are ordinarily supported on either graduated rods or on meter cables. Standard graduated rods are best adapted to low velocities and to depths not exceeding five feet. For high velocities or greater depths it is necessary to use cable of special design. The cable must be strong enough to properly support the amount of weight used, to hold the meter in place. It must also be water-proof and of high quality. The cable usually consists of No. 16 old code double insulated show window cord, which will properly support the weights generally used. For those exceptional cases where heavy weight is required, an appro- priate increase should be made in the size of the cable. The amount of weight to be used depends on the velocity of the current to be measured. A single ten pound weight will serve for the measurement of ordinary velocities. Thirty pounds weight is sufficient for all cases of ordinary practice. A single thirty pound weight is preferable, but for convenience in handling, two fifteen pound weights may be used. When more weight is used it should be in one piece and when placed on the hanger the top of the weight should be not less than six inches from the bottom of the cups. The frequency with which the revolution of the cups will be indicated depends on the velocity of the water to be measured. For velocities under four feet per second the contact indicating each single revolution should be selected, but for higher vel- ocities the contact indicating every fifth revolution should be used. Electric Register No. 609 will record satisfactorily all usual velocities with either style of contact chamber. 28 W. & L. E. GURLEY, TROY, NEW YORK ADVANTAGES OF GURLEY CURRENT METERS Reliability in service. Gurley meters have been devel- oped to meet the exacting requirements of field service. The details of construction have been improved from time to time to insure continuous reliability under actual working conditions. They may be depended upon to give accurate results under trying conditions. Simplicity of design. The details of design are extremely simple. The instrument is self-contained. There are no deli- cate adjustments required, nor are there any exposed parts to give trouble. Rigidity of construction. Gurley meters are strongly con- structed. They will resist successfully all of the stresses and shocks incident to travel and field service. Adaptability. Gurley meters are equally well adapted to the measurement of small streams and large rivers. A single meter may be used on both classes of work by simply altering the method of suspension. Size. The compactness of the Gurley meter is a material advantage. It can be packed, when traveling, in a box small enough to be carried in a hand bag. Its size is also an advan- tage in handling when in actual use. CURRENT METERS 29 COMPLETE CURRENT METER FIELD OUTFIT A complete current meter outfit for field use consists of: ( 1) Meter itself, with its rating table. (2) Telephone or other indicating device, connected up with insulated wire in circuit with dry cell and connecting plugs, ready for use. (3) Oil can, filled with clock oil. (4) Small screw driver. ( 5) Spanner wrench for dismantling the meter. ( 6) Cable for supporting the meter, equipped with snap. ( 7) Torpedo weight. ( 8) Hanger. ( 9) Hanger screw. (10) Stopwatch. (11) Rods for wading measurements. (12) Notebook, containing blueprint of rating table for the meter used, a list of special tools, equipment, and also clothing, to be carried if the trip is to be an extended one. The Notebook should also contain a supply of note forms, including: Discharge Measurement General Data, Form No. H-325 (See page 54). Current Meter Notes, Form No. H-326 (See page 55). Current Meter Notes Ice Cover, Form No. H-327 (See page 60). Inspection of Recording Register Stations (See page 140). Level Notes. Sketch Sheets. 30 W. & L. E. GURLEY, TROY, NEW YORK It will be convenient to be supplied with the following articles, which are frequently necessary or desirable for making repairs to the station equipment and for the ordinary operation of the current meter: ( 1) Parallel jaw pliers with wire cutter. (2) Bottle of special clock oil, which will not clog in cold weather. (3) Roll of insulating tape. (4) 25 - foot metallic tape. (5) 50 - foot steel tape. . ( 6) Extra pivot point. ( 7) Extra set of screws, for meter. ( 8) Extra screws, for hanger. ( 9) Extra battery, with binding posts wound with insul- ating tape. (10) Extra contact spring in rubber bushing. (11) Insulated wire. (12) Small hatchet. (13) Assortment of nails. Piece of twine. Piece of cotton cloth, for drying meter. We are prepared to supply a Time Recorder, or Stop Watch, known as No. 619, open face, nickel case, stem winder, with fly-back attachment for starting and stopping. It registers minutes, seconds and fifths of seconds. See Price List. CURRENT METERS 31 CARE OF THE CURRENT METER TO TAKE THE METER APART When taking the meter apart, remove the tail vanes and the hanger stem; then loosen the set-screw to the contact chamber, and pull the chamber out by a slight twisting motion. Care must be taken to let the cups be free to turn, so that the worm gear on the upper end of the shaft can disengage from the teeth of the contact wheel. In handling the contact chamber, it is well to take off the cap, so that the gear-wheel can be seen during the operation. The pivot-point can then be taken out and the cups released by loosening the upper part of the shaft with a spanner wrench. This wrench is so designed that it can be used for loosening all parts of the meter. In putting the meter together, first attach the cups to the cup shaft. In doing this, the upper part of the shaft should be inserted through the upper hole of the yoke before it is screwed to the lower part. Care must be taken to place the cups so that they will move counter-clockwise. After the cups have been fastened to the shaft, insert the pivot point and clamp it in place, and then insert the contact chamber. In replacing the contact chamber, the cups should be left free to move on the pivot point. Before inserting the frame nut, the pivot point should be adjusted and firmly secured with the lock-nut. The adjustment should allow a slight vertical motion of the cups. TO CHANGE CONTACT CHAMBERS 1. Loosen the set screw to the contact chamber in yoke. 2. Carefully lift the contact chamber from the yoke. 3. Carefully unscrew either the worm, or eccentric, from the shaft and screw in the other, which will be found in the small round tin box. 4. Slide into the yoke the other chamber, which is in a block in one corner of the meter box, and tighten the set screw. 32 W. & L. E. GURLEY, TROY, NEW YORK SPECIAL INSTRUCTIONS Although the current meter is substantially made, and will stand considerable hard usage, it needs careful handling and attention to insure its proper working. In this connection the following instructions should be carefully observed: 1. Be sure that the set-screws are all tightened before putting the meter in the water; otherwise, some of the parts may be lost. 2. Loosen the raising nut and see that the meter runs freely before beginning a measurement. Spin the meter cups occasionally during a measurement to see that they are running freely, that is, that they will continue to move for a considerable time at a slow velocity. 3. See that the weights play freely on the stem, so as to take the direction of the current and thus avoid an unnecessary drag on the line. 4. If any apparent inconsistency in the results of an observation throws doubt on its accuracy, investigate the cause at once. Grass may be wound around the cup shaft; the cups may be tilted by tension on the contact wire; the channel may be obstructed immediately above the meter; the meter may be in a hole; or the cups may be bent so as to come in contact with the yoke. 5. After a measurement, it is absolutely necessary to pour out any water that may have collected in the commutator box, to clean and oil the bearing (in order to prevent rust) and to inspect the pivot point. 6. When the meter is not in use, the cups should never be permitted to ride on the pivot point. 7. Always see that the lock-nut on the pivot-point is screwed firmly against the frame nut, so that it will stay in place and carry the cups properly. 8. Never use a dulled pivot. Always keep several extra pivots on hand. 9. In measuring low velocities, be sure that the meter is in a horizontal position. If it has a tendency to tip, the balance CURRENT METERS 33 weight on the tail should be adjusted or the meter be held rigidly by inserting a plug in the slot against the stem. 10. Avoid taking measurements in velocities of less than 0.5 foot per second, because the accuracy of the meter dimin- ishes as zero velocity is approached. 11. For velocities of less than 1 foot per second, the pivot point should be the same as at the time of rating, sharp and smooth. As the velocity increases, the condition of the point is less important, because the friction factor decreases. 12. In taking measurements at high velocities, sufficient weight, and a stay-line, should be used to hold the meter in a vertical position. 13. In very shallow streams the meter should be suspended from the lower hole on the stem, and the weight should be placed above. FlG - 9 14. If the cups of the meter are bent, they may be easily put in shape by pressing them with a piece of wood or metal with a round, smooth FlG 10 end. 15. The telephone re- r B ceiver is very sensitive to elec- x trie currents, and can be used ( to locate any break in the cir- cuit. First try the telephone . FlG l n , , J , ? Testing Meter Circuit. and battery together (Fig. 9) in a circuit having a make-and-break point, as at a. This may be done by using a knife blade or a screw driver, making con- nection where the wires enter the plug. If there is no click in the telephone, then the battery or the telephone does not make a circuit. If there is a click, insert the meter in the line and test for a contact in the meter head (Fig. 10) by revolving the meter wheel. If the meter is all right, put the meter cord in the circuit and test both sides either by inserting a fine needle that joins both conductors or by making double connection and touching alternate sides of the line, a. (Fig. 11). 34 W. & L. E. GURLEY, TROY, NEW YORK 16. When the meter is not in use, disconnect the meter line from the battery, so that it will not become exhausted. 17. Do not strike the telephone receiver, as a heavy jar will to a greater or less extent, demagnetize the pole pieces, and to that extent will injure the receiver. If care is taken, it is very improbable that the telephone receiver will get out of order. 18. Gare must be taken not to short-circuit the dry battery when the meter is not in use. To avoid this, the poles may be wound with insulating tape. RATING THE CURRENT METER The relation between the revolutions of the meter cups and the velocity of the water may be determined by rating each meter before it is used. Theoretically, the rating for all meters of the same make should be the same, but, as a result of slight variations in construction, and in the bearing of the wheel on the axis at different velocities, the ratings differ slightly. A meter is rated by moving it through still water with uniform speed, and noting the time, the number of revolutions, FIG. 12. Current Meter Rating Station at U. S. Bureau of Standards. CURRENT METERS 35 and the distance (Figs. 12 and 13). The revolutions per second and the velocity in feet per second are afterward com- puted from these data. Many runs are made, the speeds vary- ing from the least which will cause the wheel to revolve to several feet per second. The results of these runs, when plotted with revolutions per second and velocity in feet per second as co-ordinates, locate the points which define the meter rating curve from which the rating table is prepared. The number of revolutions of the meter wheel are indicated on an electric recorder; the distance is obtained by an electrical mechanism, which is in circuit with the meter wheel, so that the exact distance for a given number of revolutions is obtained ; and the time is taken by a chronograph or a stop-watch, which is started and stopped by means of an electrical control. Long experience has shown that with good care meters do not readily lose their adjustment. When used carefully, every day, in ordinary service, a meter should be rated once in three months as a check. Meters in similar service, but used less frequently, should be rated once a year as a check. For special work the meter should be rated before beginning and' as fre- quently as may be necessary during the work. FIG. 13. Current Meter Rating Station of Irrigation Branch, Canadian Interior Department. 36 W. & L. E. GURLEY, TROY, NEW YORK The details of rating a current meter and of preparing the meter rating curve and table are given in "River Discharge."* The rating should be done at a rating station, properly equipped to carry on the work. The rating station should be allowed ample time, usually about two weeks, to make the rating and to compute the rating table. The following table gives a list of rating stations and the cost of rating a meter: STATION ADDRESS RATING FEE U. S. Bureau of Standards, Washington, D. C. $10 for each head Rensselaer Polytechnic Institute, Troy, N. Y. $10 for each head Worcester Polytechnic Institute, Worcester, Mass. Cornell University, Ithaca, N. Y. University of Michigan, Naval Tank, Ann Arbor, Mich. Imperial Valley Development Co., Calexico, Cal. University of Toronto, Toronto, Ontario. Irrigation Branch, Department of the Interior, Calgary, Alberta. Theoretically, the wheel of a differential-action meter, when carried through still water, should revolve as a wheel revolves in passing over the ground. That is, in going a given distance it should make practically the same number of revolutions, regardless of speed. The rating of a great many small Gurley electric meters shows this number to be from 42 to 44 revolu- tions in going 100 ft. The true number of revolutions of the wheel should equal the distance of the run divided by the effective circumference of the wheel multiplied by a coefficient which depends on the retarding effect due to the pressure on the convex surface of the cups and their blanketing effect. Assuming the effective cir- cumference to be the circle passing through the points of the cups, which is 0.7854 ft., and the true number of revolutions to be 43^ per 100 ft. run; then the coefficient would be 0.342. Although complete data are not available to confirm this theory, the working of the meter shows that it holds very closely to it. The foregoing shows that the theoretical meter-rating curve is a straight line passing through the origin. If the true num- ber of revolutions made in going 100 ft. is 43^2, the equation of this curve will be X = 2.3 Y, where X = velocity, in feet per second, and Y : = revolutions per second. * " River Discharge ", by Hoyt and Grover, for sale by W. & L. E. Gurley, price $2.50, postpaid. CURRENT METERS 37 A study of the rating curves of a large number of small Gurley meters shows that, as a rule, the curve is made up of two straight lines, the extension of the lower one joining the upper one in an angle between the velocities of 8 and 9 ft. At this point there is a slight increase in the friction on the bearings of the meter wheel and shaft. Notwithstanding this break in the curve, the observed curve parallels the theoretical curve very closely. The lower part of the curve starts at a velocity of less than 0.1 ft. per second, which is required to start the wheel. In using the meter, observation is made of the number of seconds the wheel requires to make a selected number of revo- lutions. Therefore, a rating table is prepared for each meter, giving the velocities per second corresponding to the number of revolutions. The most convenient table is prepared for 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, and 200 revolu- tions, with the times of the runs ranging from 40 to 70 seconds, giving velocities from 0.19 to 11.12 feet per second. Rating Table for Use with Acoustic Current Meter, No. 616 This Table is a mean ot the ratings of many different meters, and will probably give correct values within one per cent, for any meter of its pattern when in good order. The time column is the number of seconds that have elapsed during one hundred revolutions of the wheel, there being ten revolutions to each rap. Time Velocity Time Velocity Time Velocity Time Velocity 1000 0.30 111 1.99 59 3.74 37 5.94 666 0.39 105 2.10 57 3.85 36 6.13 500 0.49 100 2.20 56 3.96 34 6.47 400 0.59 95 2.31 54 4.07 33 6.67 333 0.70 91 2.42 53 4.18 32 6.88 286 0.80 87 2.53 51 4.30 31 7.10 250 0.90 83 2,64 50 4.40 30 7.33 222 1.01 80 2.75 49 4.49 29 7.59 200 1.11 77 2.86 48 4.58 28 7.85 182 1.22 74 2.97 46 4.78 27 8.14 167 1.32 71 3.09 45 4.88 26 8.46 154 1.43 69 3.19 44 5,00 25 8.80 143 1.54 67 3.29 43 5.12 24 9.17 133 1.65 65 3.40 42 5.24 23 9.57 125 1.76 62 3.54 40 5.50 22 10.00 118 1.88 61 3.62 38 5.79 21 10.47 38 W. & L. E. GURLEY, TROY, NEW YORK Rating Table for Use with Electric Current Meters, Nos. 617, 621 and 623 This Table is based on the ratings of many meters. The comparison of the rating of meter No. 623, both penta recording and single count contact, show an agreement with this table within one per cent. Occasional ratings vary more than one per cent., when an individual rating table may be prepared. [Extract from instructions given by the Water Resources Branch of the United States Geological Survey to their Hydraulic Engineers.] VE LOCI TY II I FEE ,T PE R SE< DOND Time Time in in Seconds 5 10 20 30 40 50 60 70 80 90 100 150 200 Seconds Revs. ?evs. Revs. Revs. Revs. Revs. Revs. Revs. Revs. Revs. Revs. Revs. Revs. 40 0.31 0.58 1.13 .68 2.23 2.78 3.34 3.90 4.45 5.01 5.56 8.34 11.12 40 41 0.30 0.57 1.10 .64 2.18 2.71 3.26 3.81 4.34 4.89 5.43 8.14 10.85 41 42 0.30 0.56 1.07 .60 2.13 2.65 3.18 3.72 4.24 4.77 5.30 7.95 10.59 42 43 0.29 0.54 1.05 .56 2.08 2.59 3.11 3.63 4.14 4.66 5.18 7.77 10.34 43 44 0.28 0.53 1.03 1.53 2.03 2.53 3.04 3.55 4.04 4.55 5.06 7.59 10.10 44 45 0.28 0.52 1.01 1.50 1.99 2.48 2.97 3.47 3.95 4.45 4.95 7.42 9.87 45 46 0.28 0.51 0.99 1.47 1.95 2.43 2.90 3.39 3.87 4.35 4.84 7.26 9.65 46 47 0.27 0.50 0.97 1.44 1.91 2.38 2.84 3.32 3.79 4.26 4.74 7.11 9.45 47 48 0.26 0.49 0.95 1.41 1.87 2.33 2.78 3.25 3.71 4.17 4.64 6.96 9.25 48 49 0.26 0.48 0.93 1.38 1.83 2.28 2.72 3.18 3.63 4.09 4.54 6.81 9.06 49 50 0.26 0.47 0.91 1.35 1.79 2.23 2.67 3.12 3.56 4.01 4.45 6.67 8.89 50 51 0.25 0.46 0.90 1.32 1.75 2.19 2.62 3.06 3.49 3.93 4.36 6.54 8.72 51 52 0.25 0.46 0.88 1.29 1.72 2.15 2.57 3.00 3.42 3.85 4.28 6.42 8.56 52 53 0.24 0.45 0.86 1.27 1.69 2.11 2.52 2.94 3.36 3.78 4.20 6.30 8.40 53 54 0.24 0.44 0.85 1.25 1.66 2.07 2.47 2.88 3.30 3.71 4.12 6.18 8.24 54 55 0.24 0.43 0.83 1.23 1.63 2.03 2.43 2.83 3.24 3.64 4.05 6.07 8.09 55 56 0.23 0.43 0.82 1.21 1.60 1.99 2.39 2.78 3.18 3.58 3.98 5.96 7.95 56 57 0.23 0.42 0.80 1.19 1.57 1.96 2.35 2.73 3.12 3.52 3.91 5.86 7.81 57 58 0.22 0.41 0.79 1.17 1.54 1.93 2.31 2.68 3.07 3.46 3.84 5.76 7.68 58 59 0.22 0.41 0.78 1.15 1.51 1.90 2.27 2.63 3.02 3.40 3.77 5.66 7.55 59 60 0.22 0.40 0.77 1.13 1.48 1.87 2.23 2.59 2.97 3.34 3.71 5.56 7.42 60 61 0.22 0.39 0.75 1.11 1.46 1.84 2.19 2.55 2.92 3.29 3.65 5.47 7.30 61 62 0.21 0.39 0.74 1.09 1.44 1.81 2.16 2.51 2.87 3.24 3.59 5.38 7.18 62 63 0.21 0.38 0.73 1.07 1.42 1.78 2.13 2.47 2.82 3.19 3.53 5.30 7.07 63 64 0.21 0.38 0.72 1.05 1.40 1.75 2.10 2.43 2.77 3.14 3.48 5.22 6.96 64 65 0.20 0.37 0.71 1.03 1.38 1.72 2.07 2.39 2.73 3.09 3.43 5.14 6.85 65 66 0.20 0.37 0.70 1.02 1.36 1.69 2.04 2.35 2.69 3.04 3.38 5.06 6.75 66 67 0.20 0.36 0.69 1.01 1.34 1.66 2.01 2.32 2.65 2.99 3.33 4.98 6.65 67 68 0.20 0.36 0.68 1.00 1.32 1.64 1.98 2.29 2.61 2.95 3.28 4.91 6.55 68 69 0.19 0.35 0.67 0.99 1.30 1.62 1.95 2.26 2.57 2.91 3.23 4.84 6.45 69 70 0.19 0.35 0.66 0.98 1.28 1.60 1.92 2.23 2.53 2.87 3.18 4.77 6.36 70 CURRENT METERS 39 TYPES OF CURRENT METER MEASUREMENTS There are three classes of current meter measurements in common use. They are named from the means employed by the hydrographer in reaching the measuring points, as follows: wading, cable, and bridge measurements. Boat measurements are occasionally used (Fig. 14). The boats used for this work should be especially equipped so that all influence of the boat on the current measured is eliminated. FIG. 14. Boat equipped for Current Meter Measurements. FIG. 15. Catamaran equipped for Current Meter Measurements. 40 W. & L. E. GURLEY, TROY, NEW YORK Two ordinary boats may be quickly equipped at a small expense as a catamaran (Fig. 15), from which meters may be operated with great facility, in other than flood conditions. Precise results have been obtained in smooth water from a rig of this kind. All measuring sections that are to be maintained continu- ously should have a fairly smooth bed, a uniform velocity of current not less than 0.5 foot per second at any stage, uniformly distributed throughout the section, with no strong eddies, cross currents, or boils, a permanent control assuring a constant rela- tion between gage height and discharge, and should not be subject to marked fluctuations during the measurements. In changing conditions, the flow past the control is the essential factor, because the records of gage height and the rating table pertain to the section at the control, and not necessarily to the section in which the discharge measurements are made. A per- manent reef or ledge extending across the stream (Fig. 16), a short distance below the edge, will control the relation between gage height and discharge, even though the bed of the measur- ing section itself may change. Where no natural control exists, an artificial control (Fig. 17) may be constructed. In general, it has been found more economical in the long run to make stream measurements where the conditions are permanent, even though the cost may be greater than if the measurements were made at a more easily accessible point, but with changing conditions. CURRENT METERS 41 FIG. 16. Natural Control of a Stream. FIG. 17. Artificial Control of a Stream. 42 W. & L. E. GURLEY, TROY, NEW YORK WADING MEASUREMENTS Measurements are made by wading (Fig. 18), wherever the depth and velocity of the stream permit the hydrographer to reach all measuring points and to hold the meter in position. To mark the points at which observations are taken, it is customary to stretch a marking line across the stream. For this purpose a metallic tape may be stretched between iron rods that have slits in their ends; when there is a little wind, or for lengths not exceeding 200 feet, a braided silk fish line may be used. The line should be prepared for such use by marking it off while well stretched, into short lengths, say four feet each, with black paint, using special marks every 20 feet. When put in place for use the line is stretched until divisions are of the correct length when checked with a steel tape. For greater lengths a galvanized telephone wire, or a twisted smooth fence wire, may be used, the size of the wire being properly propor- tioned to the span. The tape or the fish line which forms part of the hydrog- rapher's kit is kept stretched across the stream only during the measurement, but wire markers are ordinarily left in place at the station. Measurements should be made according to the condition of roughness of the stream bed. Under ordinary conditions the two-tenth and eight-tenth method should be used if the meter can be properly submerged for the upper measurements. In shallow water near the bank the six-tenth method may be used. If a stream is very shallow and its bed rough, the position of the thread of mean velocity may rise to one half of the depth. The hydrographer using the wading method can get his sound- ings accurately and can set his meter exactly at the proper posi- tions. This method does not confine all measurements to a single section, but permits the hydrographer to select the most suitable section each time a measurement is made and is especially use- ful on small streams or at low stages. See page 51. In making such measurements, the engineer should stand below the tape line and to one side of the meter (Fig. 19), in order that he may not disturb its action. CURRENT METERS 43 FIG. 18. Wading Measurement. FIG. 19. Typical Gaging Station for Wading Measurement. 44 W. & L. E. GURLEY, TROY, NEW YORK MEASUREMENTS FROM CABLES Cables (Figs. 20, 21, 22, 23 and 24), afford ready means of gaging streams up to a thousand feet in width, which includes most cases. The advantage in using a cable lies in the fact that the station may be placed at the most favorable location independently of existing structures. Complete details for installing cable stations are given in (U. S. Geological Survey) Water Supply Paper No. 371. At cable stations the meter is suspended by means of the meter cable of No. 16 old code double insulated show window cord, which is thick enough to afford a comfortable grip and not cut the hands. A piece of twisted sash cord, or a specially prepared meter cord, carrying in the center an insulated wire and long enough to reach from the bottom of the stream to the surface of the water, is used between the top of the meter hanger and the meter cord in order to minimize the effect of the cur- rent. (See Fig. 1). In swift water a head line is used to hold the meter in a vertical position. It is made of a piece of No. 10 galvanized iron wire, long enough to reach from the top of the meter hanger, to which one end of it is attached, to a rope above the surface. The rope is carried to pulleys on a stay line some distance up- stream, and back to the car. The hydrographer adjusts the stay line as required. (See Fig. 21). At cable stations it is customary to use the two-tenth and eight-tenth method, taking the observation every 5 or 10 feet, according to the width of the stream. FIG. 20. Current Meter Gaging Station. CURRENT METERS 45 FIG. 21. Typical Current Meter Gaging Station with Automatic Water Stage Register. FIG. 22. Current Meter Observers in Cable Car. 46 W. & L. E. GURLEY, TROY, NEW YORK FIG. 23. Russian Government Engineers using Gurley Current Meters in Turkestan. CURRENT METERS 47 MEASUREMENTS FROM BRIDGES Occasionally bridges may be found well located as regards stream gaging. In such cases it is customary to mark off measuring points with paint on the rail or string piece of the bridge. The initial point of the series should be carefully referred to a permanent object and a careful description of the location written in the note-book. A stayline is usually stretched above the bridge to be used when high velocities prevail. Measurements from bridges are made as from cables. FIG. 24. Typical Gaging Station for Bridge Measurement. 48 W. & L. E. GURLEY, TROY, NEW YORK USE OF THE CURRENT METER The quantity of water flowing in a stream is found by means of a current meter, by subdividing the cross-section of the stream into partial areas or panels and by multiplying each partial area by the mean velocity of the water that flows past each partial section, then taking the sum of all such products. The cross-section of the stream is subdivided by verticals taken sufficiently close together to define the area accurately, as in cross-sectioning earthwork; that is to say, the lines (Fig. 24) on the stream bed between consecutive verticals should be essentially straight. On streams with smooth beds the points of observation will occur at regular intervals, but the method of computing the partial areas is not dependent on the distance apart of the verticals. The length of each vertical in feet is measured by sounding either with a sounding rod, using an engineer's level on the bank if desired, or by a weight and line. The mean velocity in each partial area is the average of the velocities in the verticals that bound the area. Velocities are measured in feet per second; hence, the product of the partial area by the mean velocities will be in cubic feet per second. One cubic foot per second, is the quantity of water that will flow past a section of the stream one foot wide and one foot deep, with a velocity of one foot per second. SOUNDINGS Rods for sounding should be of a convenient length for handling and may be made either of wood or of metal. Wooden rods should be thin and sharpened on the edges, a section 3 inches wide and 1/4 i ncn thick being appropriate for a length not exceeding five feet. Longer sounding rods may be made from 2x4 inch lumber, the edges being worked so that the cross section of the rod has the same shape as the hull of a ship. The correct style of metal rod (Fig. 6) is furnished with all Gurley meters. Where there is no danger of damaging the meter, the sound- ings are taken with the meter on the rod in all wading measure- ments. It should be noted that the zero of the graduations on the rods is at the center of the cups, so that a distance equal to the distance from the center of the cup, to the bottom of the yoke CURRENT METERS 49 should be added to each reading on the rod when sounding. In order to prevent the sounding rod sinking into the bed of the stream, it should be provided with a shoe at least 3 inches in diameter. When using the rod care should always be taken that the reading is not too high, on account of the impinging water running up the rod. If a sounding rod or line is used, the meter not being attached, the soundings are made at all measuring points before observing the velocities. The soundings from bridges or cables are usually made with the weight and line, and in such cases, with swift water, a head line is used to hold the meter in a vertical position to prevent error, due to the weight being carried down the stream or to the bowing of the line. Soundings with the line are most readily taken as follows: The weight and line are lowered until the weight touches the bed of the river directly under the measuring point and, with the line taut, a point is marked on it by grasping it with the fingers opposite a fixed point on the bridge or car; the weight is then raised until it just touches the surface of the water and the length of the sounding line that passes the fixed point is measured. This length is measured by placing the end of a linen or metallic tape opposite the fixed starting point on the sounding line, grasping both the line and the tape in the hands, and drawing up the line and tape without permitting them to slip on each other until the weight reaches the surface of the water. The length of line thus drawn up, representing the depth of the water, is then read directly from the tape. This measurement can usually be made by one person with sufficient accuracy, even when the water is from 10 to 12 feet deep. On the U. S. Geological Survey standard cable car a scale is fixed to the frame of the car for measuring the depth. VELOCITY OBSERVATIONS In making a velocity measurement, the meter is held at the point in the stream at which it is desired to ascertain the velocity of the current. The wheel is allowed to revolve for a few seconds, in order that it may adjust itself to the current, after which the time for a given number of revolutions is noted, and the velocity is obtained from the rating table for the meter. The run should be from 40 to 70 sec. ; the number of revolutions 50 W. & L. E. GURLEY, TROY, NEW YORK observed, depending on the velocity of the water, should be one of those for which the meter rating table has been prepared. A check on the work is made by repeating the observation. If the run is not repeated, a check can be obtained by noting men- tally the time for each five revolutions. A stop-watch is used for observing the time, and the record is made to the nearest /^ second. The observations should be recorded on properly prepared forms. See pages 54, 55, and 60. In discharge measurements, the mean horizontal velocity in a vertical at the measuring point is desired. Various methods are used for this determination, among which the following four are most common: (a) Vertical velocity-curve method, (b) two- tenth and eight-tenth-depth method, (c) six-tenth-depth method, and (d) sub-surface method. (a). By the vertical velocity-curve method, measurements of horizontal velocity are usually made just beneath the surface, at 0.5 ft. below the surface, and at each fifth to each tenth of the depth from the surface to the bed of the stream, and as near the bottom as possible. These measured velocities, when plotted with depths as ordinates and velocities as abscissas, define for each vertical, the vertical velocity-curve which shows the velocity at every point in the vertical, and from which the mean velocity can be determined by dividing the area bounded by the curve, the top and bottom ordinates, and the axis of depth by the total depth. The area may be found by planimeter, or by Simpson's rule or Durand's rule*, which will be found in books on elementary mechanics. Studies of vertical velocity-curves taken on many streams under various conditions of depth, velocity, and roughness of bed, show that these vertical velocity-curves have approximately the form of a parabola in which the axis, coinciding with the filament of maximum velocity, is parallel with the surface and is in general situated between the surface and one-third of the depth of the water. From the maximum the velocity decreases gradually upward to the surface and downward nearly to the bottom, where it changes more rapidly on account of the friction on the bed. As the depth and velocity increase, the curve approaches a vertical line as its limiting position. *Haneock, Applied Mechanics for Engineers. CURRENT METERS 51 The vertical velocity-curve method is valuable as a basis for the comparison of all other methods, for determining the co- efficients to be used in reducing the values obtained by other methods to the true value, for use under new and unusual con- ditions of flow, and for measurements under ice. (b). In the two-tenths-eight-tenths method, observations of velocity are taken at two points located at depths of the sur- face of 0.2 and 0.8 of the depth in the vertical in which the measurement is made. The mean velocity is taken as the mean of the velocities at these two points. This method is based on the theory* that the vertical velocity-curve is a parabola, as already stated, in which case the mean of the ordinates at 0.2114 and 0.7886 depth below the surface gives the mean ordinate. This is mathematically true for any parabola and for any position of the thread of maximum velocity. A study of a large num- ber of vertical velocity-curves shows that this holds true in Nature; and experience proves that this method gives more con- sistent results than any of the others except the vertical velocity-curve method. (c). In the sixth-tenth method, the observation of the velocity is taken at a depth from the surface equal to 0.6 of the depth of the stream. This method is also based on the theory** that the vertical velocity-curve is a parabola with the maximum abscissa between zero and one-third of the depth, in which case the mean ordinate is between 0.58 and 0.67 of the depth from the surface. A study of a large number of vertical velocity- curve measurements shows that the mean depth of the mean velocity is approximately 0.6 of the depth. This method has the advantage of requiring a less number of velocity observa- tions, and gives very satisfactory results, but not as good as those obtained by the two-tenths-eight-tenths method. (d). In the sub-surface method, the measurement of velocity is made at from 0.5 to 1 ft. below the surface, depend- ing on the depth of the stream. The meter is held at sufficient depth to be out of any surface disturbance. When this method is used, the velocity must be reduced by a coefficient to obtain *See "River Discharge," page 54. **See F. W. Hanna, M. Am. Soc. C. E., Engineering News, January 11, 1906. 52 W. & L. E. GURLEY, TROY, NEW YORK the mean velocity. This coefficient varies from 78 to 98%, depending on the depth and the velocity of the stream. The deeper the stream and the greater the velocity, the greater the coefficient. For average streams in moderate freshets, a co- efficient of 90% should be used; in flood work, a coefficient of from 90 to 95% ; and for streams at ordinary stages, from 85 to 90%. Independent discharge measurements, as a rule, are of but little value in hydraulic work unless they are taken at stages which are known to be either extremely low or extremely high. In ordinary work it is necessary to make a series of measure- ments which, with daily gage heights of the flow of the stream, make possible the computation of the total flow of the stream and also its distribution. In connection with the individual measurements, therefore, it is necessary to observe gage heights and take full notes of the conditions under which the measure- ments are made, in order to enable the construction of a station rating curve and estimate the daily discharge. RECORDING THE DATA The observations should be noted at the time they are made on properly prepared forms for discharge measurements, shown on pages 54, 55 and 60. There should be shown in these notes: In column 1. The distance from the initial point of each vertical in which soundings and velocity observations were made. The distance between successive stations gives the width of the partial area. The widths are written in column 11. 2. The depth of water in the vertical at which the observa- tion was made, as determined by the sounding. 3. The depth from the surface down to that point in the vertical at which the velocity observation was made. This item is computed mentally in the field before making the velocity observation, and will be two-tenths, six-tenths, eight-tenths, etc., of the depth recorded in column 2, depending on the method used in making the measurement. CURRENT METERS 53 4. The duration of the velocity observation in seconds as determined by means of the stop-watch. 5. The number of revolutions of the cups in the time noted in column 4. For convenience in computing, the number of revolutions should be one of those appearing in the rating table for the meter used. Computation of the quantities to fill in the remaining col- umns of the form are made as follows: Column 6. Shows the velocity of the water as given by the meter at the point noted in column 3, and is taken from that column of the rating table at the head of which appears the number of revolutions shown in column 5, opposite the number of seconds, noted in column 4. Columns 3, 4, 5 and 6 are completely filled in for each line on which an observation is noted. 7. The mean velocity in the vertical at any measuring point is the average of the velocity observations made in that vertical. When a single velocity observation is made in any vertical the value shown in column 7 will be the same as that shown in column 6. 8. To get the mean in the section, or partial area, take values for consecutive verticals from column 7 and write their average in column 8. 9. The number of square feet in each section or partial area shown in this column is the product of the mean depth given in column 10, and the width as given in column 11, ob- tained from notes in column 1 as explained for that column. 10. The mean depth of each partial area is computed by averaging the depth (column 2) at each vertical with the depth (column 2) at the following vertical. 11. The width is the difference between the distances from the initial point of consecutive verticals. 12. The discharge for each section or partial area is the product of factors given in columns 8 and 9. Not more than three significant figures should be used in the computations. Columns 9 and 12 are added and the sum of the products in column 12 divided by those in column 9 to get the mean 54 W. & L. E. GURLEY, TROY, NEW YORK FORM NO. H-325 Date. PUBLISHED BY W. &. L. E. GURLEY Engineering Instrument Makers TROY N. Y. ^_^^^^_________ FILE DISCHARGE MEASUREMENT NOTES , 191 No. of Meas. River at y State of. Creek near Width Area Mean Vel Cor. M. G. H.. Party Disch. Staff gage, checked with level and found Gage reading Time Station Weighted mear Correct i G Ht ...ft. " " ....ft. Chain length, checked with steel tape, 12-lb. pull, found ft. " " changed to ft. at o'clock. Correct length ft. " '* corrected on basis of levels to.... ft. at o'clock. Meter No. Date rated Meas. began ; ended Time of meas. (hrs) Method No. meas. see's Coef Av. width sec Av. depth G. Ht. change (total.) % diff.by rating table. Meas. from cable, bridge, boat, wading. Meas. at ft above, below gage. If not at regular section note location and conditions Area from soundings (date) Method of suspension , Stay wire Approx. dist. to W. S Arrangement of weights and meter; top hole ; middle hole ; bottom hole Gage inspected, found ..... Cable inspected, found , Distance apart of measuring points verified with steel tape and found Wind upstr., downstr., across. Angle of current Observer seen G. Ht. book inspected Examine station locality and report any abnormal conditions which might change relation of G. Ht. to disch., e. g., change of control; ice or debris on control ; backwater from; condition of station eauioment.... Sheet No. 1 of sheets, [f in ufficient space, use back of sheet, with reference letters, FIG. 25. Form No. H-325. Discharge Measurement, General Data CURRENT METERS 55 FORM NO. PUBLISHED BY H-326 W. 4. L. E. GURLEY Engineering Instrument Makers TROY. N. Y.. U S. A. DISCHARGE MEASUREMENT NOTES 192 No. of Meas. River, at Dist. from initial point Depth Depth of ob- servat. Time in sec- onds Rev- olu- tions VELOCITY Area Mean Depth Width Discharge At point Mean in ver- tical Mean in Sec- tion' Totals No. of Sheets. Comp. by Chk. by FIG. 26. Form No. H-326, Current Meter Notes. 56 W. & L. E. GURLEY, TROY, NEW YORK velocity in the entire cross-section. The mean velocity, total area and total discharge, are noted in the appropriate place on the form. The preceding method of calculation may be summed up in the following expression: FIG. 27 Cross-Section of Stream to Illustrate Discharge Measurement Computation. In this formula, do, di, d2 .... dn and vo, vi, V2 .... vn are the depths and velocities at the respective measuring sections ao, ai, 02 .... an, which are spaced at the distances h, L>, Is .... In, which is easily used as explained above and which gives accurate results.* The field notes for each measurement, including a properly filled in copy of sheet 1, should be fastened together securely. This form, which is shown on page 54, should be filled in as soon as the field notes have been computed. The computations should be made before leaving the station. If the measure- ment does not plot within the limit of precision established for the work, the computation should be carefully reviewed and if necessary the measurement should be repeated. It is of great importance to use the correct gage height ^hen plotting a measurement. The gage height should be read at frequent intervals during the measurement, and the reading *For a discussion of computation of discharge measurements by various formulas, see article by Mr. J. C. Stevens, M. Am. Soc. C. E., in Engineering News, June 25, 1908. CURRENT METERS 57 noted, together with the time. The vertical at which measure- ment is being made at the time of reading the gage should also be shown in the notes. At a recording gage station this distance from the initial point at which measurement is being made at even hours (or fractions thereof) if the stage is changing, is noted as the measurement progresses, and the corresponding gage heights are later taken from the automatic register. At non-recording stations, the gage height is noted similarly by reading either the gage itself, or else distances above or below a more conveniently placed reference point, whose index is in known relation to the gage height. To give proper weight to the gage height readings, take the average of the first and second gage heights and multiply that average by the discharge that has been computed for that part of the cross-section between the vertical in which observation was made at the time of reading the first gage height, and the vertical corresponding to the time reading of the second gage height. Proceed similarly for the second and third gage heights, third and fourth, fourth and fifth, and so on, multiplying each average gage height by the corresponding partial discharge. Sum up all the products of average gage height and partial discharge and divide this sum by the total discharge as com- puted by adding up column 12. The quotient is the required weighted mean gage height. FIG. 28 Winter Measurement. CURRENT METERS 59 LOW WATER MEASUREMENTS At many stations the velocity of the river at low stages is so small that it may be advisable to find a section nearby in which the meter measurement may be made by wading. For such measurements, the meter on the rod (Fig. 3) is the most satisfactory. In order to obtain a suitable section, it may be necessary to cut off part of the flow by damming the stream and modify- ing the channel so as to get sufficient depth and velocity for measuring. MEASUREMENTS UNDER ICE When a discharge measurement is to be made under ice, it is first necessary to find a good measuring section. Such a reconnoissance can best be made by a hydrographer who is familiar with the stream and who knows where he will find sections of the stream with smooth beds. A hole is first chopped through the ice at the center of the stream at a section being investigated. If this hole shows that little or no slush ice is present, and the velocity is measurable, further investigations should be made at each side. It has been found that sections free of slush or anchor ice are most com- monly found just above an open place on the river. After the measuring section has been selected a hole is chopped through the ice at each measuring point, and the depth and velocity determined with the meter on the rod. Where the depth and velocity are too great the work will have to be done with the meter suspended on the meter cable. Ice measurements are usually made by the .2 and .8 method, and sometimes by vertical curves. The soundings should be made to determine the depth from the bottom of the ice to the bed of the stream and the meter observations taken at .2 and .8 of this depth. In all other respects ice measurements are made and computed in the same way as open water measure- ments. The special jointed ice chisel, ice-measuring stick and carrying bag, generally used in connection with ice measure- ments, are illustrated in Fig. 33. 60 W. & L. E. GURLEY, TROY, NEW YORK .2 depth -- ' =(c-b)x.2+b 3 :^^>^^w^ OBSERVATIONS )istance from initial point Thickness of ice Total depth of water Depth of meter from water surface Time in seconds Revolutions Water surface to bottom of ice Effective water depth 10 a -b C c-T> (c-b)x.2+b (c-b)x5+b (c-b)*.8+b 15 _ J FIG. 32 Diagram indicating notation used in making Discharge Measurements under Ice, with Form for Notes. The notation and a form for recording the data are illus- trated in Fig. 32. The remaining seven columns are similar to those in Form No. H-326 (See page 55). CURRENT METERS 61 Solid FIG. 33 Ice Chisel, Ice Measuring Stick, and Bag. FIG. 34 Winter Measurement. 62 W. & L. E. GURLEY, TROY, NEW YORK MEASUREMENTS IN ARTIFICIAL CHANNELS Current meter measurements of the flow of water in artificial channels must be made with special care, as the laws of flow for open channels are not always applicable to artificial ones, because the water level may be subjected to disturbing influ- ences such as undercurrents caused by intakes and outlets at rapid velocities. Current meters have been employed in measuring the flow in large conduits. In such cases apparatus designed to hold the meter at a definite point in the cross-section has been used. The description of such apparatus will be found in the Transac- tions of the American Society of Civil Engineers, 1910, Vol. 66. Current meters have also been used successfully for measuring the flow of sanitary sewers. Details of this work are given on page 142. ACCURACY AND RELIABILITY OF THE CURRENT METER When considering the accuracy of results obtained by the current meter, account should be taken of the use to be made of the data. It must be remembered that both the total flow of the stream and its distribution over the drainage area are con- stantly changing, and that the conditions over the drainage area are constantly changing, and that the conditions existing at any given time will probably never occur again. The flow which may be expected in any stream, therefore, can be determined only by studying a series of records extending over a long period; for this reason the degree of refinement with which the measurements are made should be appropriate to the use to which they are to be put. As with most instruments, the accuracy and reliability of the current meter depend largely on the care taken in the measurement and the propriety of the method used. CURRENT METERS 63 SELECTION AND LOCATION OF GAGING STATIONS RECONNOISSANCE To obtain the best results with a current meter, stations should be located only at sites well adapted to its use. The same careful attention should be given to the selection of a current meter station as is given in establishing a system of control points for a topographic survey, in which case the entire problem is considered from all view points, only such control points being located as will give consistent and accurate results. The final location of the gaging station and the choice of equipment to be installed will depend very largely on a thorough reconnoissance. This work is of equal, if not greater, impor- tance than any other detail connected with the location of a gaging station. It should be performed by an engineer exper- ienced in stream gaging work. Poor results obtained at many stations may be traced directly to the fact that such stations are not properly located. When selecting and equipping a station, while considering the present use of the data to be obtained there, the importance of all possible uses for which the records may be required in the future, under changed conditions, should be kept well in mind, and all the requirements should be coordinated as com- pletely as circumstances permit. If the greatest immediate value of the data is for a power study in a given drainage area, locate at or near the center of the power zone a primary or base station, and elsewhere as many secondary stations as may be necessary. For this par- ticular case, as in any other water supply problem, the base station should be placed at the strategic point on the main stream, and all data collected in the basin should be compared with the data obtained at the base station. As the object of the reconnoissance is to find the best loca- tion that will furnish the desired data, it is well before locating the primary station to examine the locality carefully during various stages of flow, considering the stream under ice con- ditions, as well as during the summer season. At low stages the bed and the minimum velocity can be examined, and some 64 W. & L. E. GURLEY, TROY, NEW YORK estimate of high water conditions can also be made, while at medium and high stages it is usually impossible to examine the bed or estimate low stage velocities. A stream in a lumbering section must be watched closely during the log-driving period. Locations at which log jams usually form should be avoided. When the problem of locating stations involves an entire drainage basin, an hydraulic engineer familiar with the basin will likely have in mind tentative locations for the primary station and for supplementary stations, and will extend his reconnoissance by making examinations at different river stages at numerous points in the basin as he may have occasion to go back and forth in it. For locating secondary stations care- ful reconnoissances are also required, but they are usually made more rapidly. If the project for which the data are collected depends on continuous flow, and there are few or no storage possibilities, the essential data will be that giving the amount of the minimum flow, and the period for which it continues. If opportunities for storage do exist, then the maximum flow will be of equal importance. Satisfactory results are usually obtained if these two extreme conditions are allowed to determine the location of the station. The following essentials should be carefully examined: 1. The general course of the stream above, at and below, the station, noting whether the course of the stream is straight or whether curved. 2. The average depth and velocity of the stream at the section under consideration. 3. The character and location of the control point, with reference to the proposed location of the gage. 4. The character of the stream bed, whether of sand, gravel, boulders or rock, and especially whether it is shifting or permanent. 5. The character of the stream banks at the proposed section, whether high or low, clear or wooded, permanent or changing. 6. The relative position of dams and the mouth of tribu- tary streams relative to the proposed location, considering CURRENT METERS 65 carefully the effect of these on the gage heights and the measurements. 7. The availability of observers or attendants, and their qualifications for the work. 8. The most appropriate type of gage, whether recording or non-recording. If no records are available concerning the diurnal fluctua- tions, such records should be secured at once by installing a portable automatic register (See Register No. 633, Fig. 48). The results of this test will show whether an automatic gage installation is necessary. 9. For an automatic water stage register, a survey of the location decided upon, to fix the character of the soil in which the well must be dug, the depth of the well, and the length of the intake pipe; for a vertical staff gage, the character of sup- port available and the length of gage rod required; for an inclined staff gage, the character of the banks, the nature of the support for the gage, and its length; for a chain gage, the character of support available and the length of chain required. 10. The available or required structures from which to make measurements. If a bridge, a general sketch of the vicinity showing especially high water lines, and a sketch of the bridge itself, showing the material of which it is built, the length and number of spans, and its height above water. If a cable, the length of span, the kind and height of sup- ports available or required, and the foundation available for them. Some practical details* will be of assistance. The principal sources of error in gaging streams by current meters are due to the effect on the water stage of slack or nearly slack water in any part of the cross-section, to backwater from dams or other obstructions, or from tributaries, which may cause the river stage to rise without a proportional increase in discharge, and from obstructing ice. Do not choose a site immediately above or below the junction of two important branches. Fig. 35 shows a gaging station where the reconnoissance was *These suggestions have been taken from a paper by C. C. Covert, M. Am. Soc. C. E., District Engineer, TL S. Geological Survey. 66 W. & L. E. GURLEY, TROY, NEW YORK hurriedly made, and where the gages were put in without any consideration to the effect of their location on the resulting records. The example given is that of two gaging stations on an eastern river, one on the east branch and the other on the the west branch. From the gages to the junction of the two branches is approximately one and a half miles. The differ- ence of elevation of the water surface at the two points is less than two feet at all normal stages. During high water periods there is always back water at one or both of the gages. While it is possible to determine the amount of back water, it would be expensive, and would have to be repeated at each successive flood, because the different conditions of flow produce different conditions of back water. On the west branch of the stream a chain gage was located near the center of a suspension bridge. About I Ki June f/ an r/ftast Location FIG. 25 Shoving poor location of Gaging Station, because of junction of two branches causing backwater. The location of gages at each station is also poor. CURRENT METERS 67 This is an extremely bad arrangement. There may be con- siderable stretch to the chain, but the uncertainty as to the amount of rise and fall due to expansion and contraction of the suspension bridge is even more than the stretch of the chain. At this station there was an opportunity to anchor the chain gage to one of the towers and to install a staff gage on the rocks, the shore on the left side beneath the bridge being rocky and almost vertical. At the station on the east branch the chain gage is used suspended from the upstream side of the highway bridge. A short distance below the highway bridge is a railroad bridge. This railroad bridge invariably causes back water at the high- way bridge during the breakup of the ice. Had the gage at this Rather fa* proi/nct extreme FIG. 36 Showing proper and improper location of Gaging Stations. 68 W. & L. E. GURLEY, TROY, NEW YORK station been a staff gage and fastened to the downstream side of the railroad bridge, the records would never have been affected by the back water from either bridge, since the control- ing point for stream flow under natural conditions is 300 ft. or 400 ft. below the railroad bridge. The records would then have given much better results during the high stages. O/d dam part /a My desirqyed Large bov/c/ers ar?d wry rough c/?as?/?e/ cavse L o Time Scale, 7 days, 4 days, or 1 day Patented August 4, 1914. Fig. 48 on page 105 illustrates an improved Graphic Register having several unique and valuable features. It is of simple construction, with few parts; is designed for easy operation, and adapted for a wide range of conditions. Its construction is such that no lost motion will develop from continuous service and it can be operated with minimum care and expense. The following vertical scales can be furnished: to 1 foot, to 5 feet, to 15 feet, to V/2 feet, to 6 feet, to 20 feet, Oto2 feet, Oto 8 feet, to V/2 meters, to 3 feet, to 10 feet, to 3 meters. to 4 feet, to 12 feet, A time scale of 1 day, 4 days, or 7 days can be furnished. As the record of stage is made around the cylinder, there is no limit to the number of revolutions possible and, hence, to the range of stage. Therefore, it is advisable to use as low a range as possible and hence a more accurate reading of the water stage. If occasionally the water stage is above the range of the register, no trouble will be experienced in reading the water level. ADVANTAGES OF GURLEY GRAPHIC REGISTERS Constancy of performance. These registers have been brought to their present high state of excellence through years of experiment. They have been developed to meet actual field conditions and are performing with satisfaction under a great variety of physical conditions in all parts of the world. Once properly installed they require a minimum of attention. Low cost. From the standpoint of maintenance and operation Gurley Water Stage Registers represent the smallest possible permanent investment. First cost is also reduced to a minimum in these registers. WATER STAGE REGISTERS 103 Mechanical excellence. Every part is made of properly selected material finely finished to insure accuracy of operation. The superior mechanical execution is accomplished by expert workmen in a factory that has been producing precision instru- ments for the past seventy-six years. Reliability of the time parts. Only properly adapted clocks are used in Gurley registers. They have properly proportioned springs and the escapement has jewelled bearings to insure uniformity of rate. The time screws that drive the pencil carriage are machined with great accuracy, thus insuring a uniform movement of the pencil over the record sheet. Unlimited range of stage. The record of stage is made around the cylinder, the time record along its axis and the cylinder revolves as the stage changes. There is no limit to the number of revolutions possible and hence to the range of stage, while at the same time the movement of the pencil is always in one direction, which assists materially in interpreting the record. Portability. The light weight of these registers renders them easily portable and hence adapts them to those special hydraulic investigations during which it is necessary to make frequent changes in the position of the register. Type of record. The hydrograph or curve recording the stage and time is continuous over seven days and presents graphically all of the fluctuations of stage and their time rela- tions. These are shown at a glance by the curve, which is a picture record of conditions. This type of record has many advantages and is especially useful in many situations. Simplicity of the record. The graphic record is easily interpreted and where desired, may be quickly reduced to statistical form. Precision and convenience in changing record sheets. The record sheets are cut to fit the cylinder closely and the pencil carriage is adjustable, thus insuring an accurate setting of the time. The cylinder is securely locked in place while changing the record sheet. The permanence of the setting of the register to the bench mark. The slot which extends through the entire length of the recording cylinder and the two guards that prevent the perfor- 104 W. & L. E. GURLEY, TROY, NEW YORK ated phosphor bronze band from accidentally slipping over the spines on the sprocket wheel when the record is being taken off, prevent any change or mistake being made by the observer while handling the register, after it has been properly installed by the engineer in charge. Changing the range of the register. Simplicity in changing two gears to alter the range of the register. Size of sheets. The record sheets are adapted to convenient filing in standard filing equipment. CONSTRUCTION OF No. 633 GRAPHIC REGISTER (The part numbers refer to Fig. 49) The base (1) supports the mechanism of the register. An extra heavy eight-day clock (2) is geared to two time screws (3), which are supported at each end as shown. The clock has two large driving springs and has jewelled bearings on the escapement shaft. Mounted on the two screws is the pencil carriage (4) which moves forward without lost motion, in accord with the turning of the clock shaft, and which can be lifted up from one position on the screws and placed in another, if desired. The pencil (11) is held in the pencil holder (5), which is free to move vertically in a cylinder (6) projecting from the upper side of the base of the carriage (4). The pencil holder (5) is set and the pencil clamped with a screw (25), so that the weight of the pencil and holder presses down against the paper. The record cylinder (8), on which the paper is placed, is supported at each end as shown. The sprocket wheel (7) is attached to the sprocket wheel shaft (26), and revolves in an eccentric bushing (24). The gear (20) is clamped to the sprocket wheel shaft by the nut (15). The gear (21) is clamped to the cylinder (8) by three small screws. Two guards (9 and 10) prevent the band from slipping over the spines on the sprocket wheel. The bolt (13) is used to lock the cylinder, while changing the record sheet. Extending across the face of the record cylinder (8) is a slot (12), which indicates the point of zero gage height on the record cylinder. Idler pulley (17) is used to spread the metal band so that the counterweight will pass the float. There is a gear (19) on the WATER STAGE REGISTERS 105 FIG. 48 No. 633 Gurley Graphic Water Stage Register, with Spring-driven Clock. Normal Range, to 10 feet. Time Scale, 7 days. For modifications in vertical range and time scale, see page 102. (See Record Sheet illustrated on page 117.) 106 W. & L. E. GURLEY, TROY, NEW YORK center clock shaft. The capstan head screw (18) is used for clamping the gear (19) to the clock shaft. Three nuts (22) serve to hold the cover on the register. Clamp screw (23) is to clamp the bushing in the base ( 1 ) . In the standard register of this type the pencil travels along the cylinder in seven days time (one inch for each day). It is possible, however, to substitute other screws (3) of such a lead that the pencil will move across the cylinder in four days (two inches for each day), or screws that will move the pencil across the cylinder in one day (eight inches per day). Such an arrangement would be very desirable in situations where there are sudden fluctuations in stage. A float 10 inches in diameter and 5 l /2 inches thick, is used. The whole instrument is enclosed in a sheet metal cover (34), FIG. 49. Diagram of No. 633 Gurley Graphic Register. WATER STAGE REGISTERS 107 FIG. 50 No. 636 Gurley Graphic Water Stage Register, with Weight-driven Clock. Normal Range, to 10 feet Time Scale, 7 days. For modifications in vertical range and time scale, see page 102. (See Record Sheet illustrated on page 117.) 15 inches long, 8/4 inches wide and 11/4 inches high, which makes it waterproof and dustproof . Weight-driven Graphic Register No. 636, shown in Fig. 50, is similar to Register No. 633, with the exception of the clock, which is weight-driven, the weights falling at the rate of 10 108 W. & L. E. GURLEY, TROY, NEW YORK inches per day. If this register is set high enough above the water, the pencil can be made to travel across the paper in two weeks, or at the rate of /^ inch per day. INSTALLATION AND OPERATION OF GURLEY GRAPHIC REGISTERS Nos. 633 AND 636 A large element in the satisfactory operation of an auto- matic register is proper installation. The results from the best register will be impaired by improper installation, whereas a register properly installed will give a record the accuracy of which depends solely on the adequacy of the instrument. The value of approximate results is not commensurate with the expense of an automatic register; therefore, the method of installation should be so thorough as to insure accuracy. In installing an automatic register, it is necessary to provide a well for the float, connected with the water to be measured by an intake pipe. If necessary, a valve should be used in the well on the intake pipe, so that the water can be throttled to prevent any surge appearing on the record sheet. To place the register permanently. The register is usually placed on a table having holes cut for the phosphor bronze band. Place the register in its proper position and fasten it to the table by the quarter-inch bolts that are furnished. Attach the metal band to the float; lower the float to the surface of the water; bring the metal band up through the table and over the sprocket wheel; then down through the table and attach the counterweight. To place the pencil carriage on the screws. The pencil carriage is engraved, "Toward clock". It is important to place the carriage on the screws in the correct position. To do this, tip the carriage so that one side will fit on the screw, then swing down as on a hinge until it rests on the other screw. To set the pencil to the exact height. Insert the record sheet in the 24 inch deep slot which extends through the entire length of the recording cylinder. This will hold the paper securely and always bring the sheets in the same position on the cylinder. Loosen nut (15)-. The pencil point being the index, hold the sprocket wheel so it cannot move. Turning the WATER STAGE REGISTERS 109 recording cylinder until the pencil indicates on the paper the correct height of the water, clamp the gear (20) to the sprocket wheel (7) with the nut (15). To set the pencil to the exact time, loosen the capstan head screw (18), revolve the screws (3) by turning gear (19) with an adjusting pin, until the pencil point indicates the exact time; hold the gear (19) with an adjusting pin, and clamp the gear (19) to the clock shaft with the screw (18). To change the record sheet, raise the float by turning the record cylinder (8) and lock it by the bolt (13), thus bringing the slot (12) in the most convenient position. Cut the adhesive paper on the margin of the record sheet. With finger on the inside of the cylinder (8), push out the ends of the record sheet, which can readily be taken off from the outside of the cylinder. Insert the corner of the new sheet that indicates the FIG. 51 Showing method of inserting ends of the Record Sheet in the Slot in the Cylinder. highest gage height; gradually press it into the slot until the upper end of the sheet is in the slot; bring the paper around the cylinder and insert the corner of the sheet marked 0, pressing it in without kinking the paper until that end is in slot (12). (See Fig. 51). Stick a small piece of adhesive paper on the margin and over the slot. When folding the edge of the record sheets, be careful to keep the folded edge straight or trouble will be experienced in inserting the record sheet in the slot in the cylinder. Care of the record sheets. It will facilitate putting record sheets on the cylinder if after folding the edge, about twelve record sheets are put in a 2-inch paper tube with rulings toward 110 W. & L. E. GURLEY, TROY, NEW YORK the outside. Roll and put one sheet in at a time, so when one is to be put on the register, it will not be necessary to take all of the sheets out of the tube. Keep the sheets in a dry place, so that the paper will be hard while inserting the record sheet in the cylinder. If it is desirable to keep the record sheets in the gage house, the paper tube with the record sheets should be kept in a two-quart fruit jar, and when taking record sheets out, open and close the jar as quickly as possible. If the atmosphere is damp when filling the jar with record sheets, place the jar with the sheets in a hot place and when heated thoroughly, put a rubber ring on the jar and screw on the cover. To oil the register. The clock will run two years with one oiling; however, if it stands idle for one month, it will be necessary to take off the hands and face and oil it with the best clock oil. The bearings of the screws and of the cylinder should be oiled with the above mentioned oil about four times a year. A very small amount of oil should be used on the screws every month. A fine wire should be used in applying the oil. INSTRUCTION FOR CHANGING THE RANGE OF GURLEY GRAPHIC REGISTERS Nos. 633 AND 636 First. Remove nut (15) under the cylinder which clamps small gear (20). Second. Remove the two hexagonal nuts (22), support cylinder (8) and time screws (3) so that they cannot fall out and become strained ; remove the back bearing, then the cylinder and time screws. Third. Change large gear (21) on cylinder, and small gear (20) on sprocket wheel shaft (26). Fourth. Loosen clamp screw (23) under clock, turn eccen- tric bushing (24) to lowest point. (Be sure that bearings are clean and oiled.) Fifth. Replace cylinder and time screws. (The time screw gears and the center gear (19) on the clock are marked "Front" "Back." Sixth. Turn the eccentric bushing (24) until there is a very slight play in meshing the range gears. Then tighten the large clamp screw (23). Seventh. Set the pencil to indicate the correct height of the water and tighten nut (15). WATER STAGE REGISTERS 111 Gurley Graphic Water Stage Register Normal Vertical Range, to 1 foot Natural Scale. Time Scale, 7 Days, 4 Days, or 1 Day. Patented August 4, 1914. This register may be used as a natural scale graphic register of great accuracy for a normal range of one foot. Multiples thereof are recorded as complete revolutions of the cylinder. The float furnished with the register is 10 inches in diameter. The power of the weight of a column of water 10 inches in diameter and 1/100 of a foot high is 5.47 ounces. Thus this float gives great lifting power and corresponding accuracy. The natural scale register is designed to meet those require- ments which demand a full size record of stage. As usually constructed the time scale is 1 inch per day, but it is possible to arrange special screws to other scales. This register is especially adapted to the measurement of the flow of any liquid over weirs. It will give the height of liquid on the weir with great precision. For this purpose it is easily applied to ( 1) Sewage disposal works, ( 2) Sanitary sewers, ( 3) Irrigation works, ( 4) Venturi flumes. It is equally well adapted to use (5) In stream gaging, ( 6) On power canals, ( 7) On irrigation canals, ( 8) On navigation canals, (9) On drainage canals, (10) In reservoirs of all kinds, (11) In measuring flow from pumps, wells, etc. (12) As a portable gage for use in special studies and investigations. Its construction is such that no lost motion will develop from continuous service and it can be operated with minimum care and expense. This instrument is a perfect weir gage and 112 W. & L. E. GURLEY, TROY, NEW YORK FIG. 52 No. 634 Gurley Graphic Water Stage Register. Normal Range, to 1 foot Natural Scale. Time Scale, 7 days. (See Record Sheet illustrated on page 118.) If this register is equipped with a sprocket wheel 2 feet in circumfer- ence, instead of 1 foot, as on Register No. 63> t , the range of the instrument is from to 2 feet, and it is Kncwn as Register No. 634-A. WATER STAGE REGISTERS 113 has no equal in simplicity of construction, accuracy, ease of operation, and durability. These Gurley registers are being used extensively by different Departments of the United States Government; also by many municipalities in connection with their sewer systems and sewage disposal plants. ADVANTAGES OF GURLEY GRAPHIC REGISTERS The advantages of Registers Nos. 634 and 634-A are the same as those given under Registers Nos. 633 and 636, on pages 102 to 104. CONSTRUCTION OF No. 634 GRAPHIC REGISTER (The part numbers refer to Fig. 53) The base (1) supports the mechanism of the register. An extra heavy eight-day clock (2) is geared to two time screws (3) supported at each end, as shown. The clock has two large driving springs and has jewelled bearings on the escapement shaft. Mounted on the two screws is the pencil carriage (6) which moves forward without lost motion, in accord with the turning of the clock shaft, and which can be lifted up from one position on the screws and placed in another, if desired. The pencil (11) is held in a pencil holder (5) which is free to move vertically in a cylinder projecting from the upper side of the base of the carriage (4). The pencil holder (5) is set and clamped with a screw, so that the weight of the pencil and the holder presses down against the paper. The recording cylinder (8), on which the paper is placed, is supported at each end, as shown. The sprocket wheel (7) is movable on the cylinder axis and is clamped to the cylinder (8) by the nut (15). Two guards (9 and 10) prevent the band from slipping over the spines on the sprocket wheel, and bolt (13) is used to lock the cylinder, while changing the record sheet. Extending across the face of the recording cylinder (8) is a slot (12), which indicates the point of zero gage height on the record cylinder. In the standard register of this type the pencil travels along the cylinder in seven days time. It is possible, however, to substitute other screws (3) of such a lead that the pencil will 114 W. & L. E. GURLEY, TROY, NEW YORK move across the cylinder in either four days, or twenty-four hours. Such an arrangement would be very desirable in situations where there are sudden fluctuations in stage. Idler pulleys (17) are to be used when it is necessary to allow the counterweight to pass the float. On the center clock shaft is a gear (19), which is clamped on the shaft by capstan head screw (18). FIG. 53. Diagram of No. 634 Gurley Graphic Register. A float 10 inches in diameter and 5^ inches thick is used. The whole instrument is enclosed in a sheet metal cover (14), 1524 inches long, l l /2 inches wide, and 9 inches high, which makes it water-proof and dust-proof. The extension (16) is for locking the cover on the register. INSTALLATION AND OPERATION OF GURLEY GRAPHIC REGISTERS Nos. 634 AND 634-A A large element in the satisfactory operation of an auto- matic register is proper installation. The results from the best register will be impaired by improper installation, whereas a register properly installed will give a record the accuracy of WATER STAGE REGISTERS 115 which depends solely on the adequacy of the instrument. The value of approximate results is not commensurate with the expense of an automatic register; therefore, the method of installation should be so thorough as to insure accuracy. In installing an automatic register, it is necessary to provide a well for the float, connected with the water to be measured by an intake pipe. If necessary, a valve should be used in the well on the intake pipe, so that the water can be throttled to prevent any surge appearing on the record sheet. To place the register permanently. The register is usually placed on a table having holes cut out for the phosphor bronze band. Place the register in its proper position and fasten it to the table by the quarter-inch bolts that are furnished. Attach the metal band to the float; lower the float to the surface of the water; bring the metal band up through the table and over the sprocket wheel; then down through the table and attach the counterweight. If the register is set high enough, it is unnecessary to pass the metal band over the pulleys (17). To place the pencil carriage on the screws. The pencil carriage is engraved, "Toward clock." It is important to place the carriage on the screws in the correct position. To do this, tip the carriage so that one side will fit on the screw, then swing down as on a hinge until it rests on the other screw. To set the pencil to the exact height. Insert the record sheet in the % inch deep slot which extends through the entire length of the recording cylinder. This will hold the paper securely and always bring the sheets in the same position on the cylinder. Loosen the nut (15). The pencil point being the index, hold the sprocket wheel so it cannot move; turn the recording cylinder until the pencil indicates on the paper the correct height of the water; and clamp the sprocket wheel (7) to the cylinder (8) with the nut (15). To set the pencil to the exact time, loosen the capstan head screw (18), revolve the screws (3) by turning gear (19) with an adjusting pin until the pencil point indicates the exact time; hold the gear (19) with an adjusting pin, and clamp the gear (19) to the clock shaft with the screw (18). To change the record sheet, raise the float by turning the record cylinder (8) and lock it by the bolt (13), thus bringing 116 W. & L. E. GURLEY, TROY, NEW YORK the slot (12) in the most convenient position. Cut the adhesive paper on the margin of the record sheet. With finger on the inside of the cylinder (8), push out the ends of the record sheet, which can readily be taken off from the outside of the cylinder. Insert the corner of the new sheet marked 1.00; gradually press it into the slot until the upper end of the sheet is in the slot; bring the paper around the cylinder and insert the corner of the sheet marked 0, pressing it in without kinking the paper until the end is in slot (12). (See Fig. 51, page 109). Stick a small piece of adhesive paper on the margin and over the slot. When folding the edge of the record sheets, be careful to keep the folded edge straight, or trouble will be experienced in inserting the record sheet in the slot in the cylinder. Care of the record sheets. It will facilitate putting record sheets on the cylinder if after folding the edges, about twelve record sheets are put in a 2-inch paper tube with rulings toward the outside. Roll and put one sheet in at a time, so when one is to be put on the register, it will not be necessary to take all of the sheets out of the tube. Keep the sheets in a dry place, so that the paper will be hard while inserting the record sheet in the cylinder. If it is desirable to keep the record sheets in the gage house, the paper tube with the record sheets should be kept in a two-quart fruit jar, and when taking record sheets out, open and close the jar as quickly as possible. If the atmosphere is damp when filling the jar with record sheets, place the jar with the sheets in a hot place and when heated thoroughly, put a rubber ring on the jar and screw on the cover. To oil the register. The clock will run two years with one oiling; however, if it stands idle for one month, it will be necessary to take off the hands and face and oil it with the best clock oil. The bearings of the screws and of the cylinder should be oiled with the above mentioned oil about four times a year. A very small amount of oil should be used on the screws every month. A fine wire should be used in applying the oil. WATER STAGE REGISTERS 117 GURLEY SEVEN DAY GRAPHIC REGISTER FIG. 54 Record Sheet for No. 633 or No. 636 Graphic Register. Normal range, to 10 feet. Time scale, 7 days. See pages 104 and 107. 118 W. & L. E. GURLEY, TROY, NEW YORK FIG. 55 Record Sheet for No. 634 Graphic Register. Normal range, to 1 foot Natural Scale. Time Scale, 7 days. See page 112. WATER STAGE REGISTERS 119 Gurley Long Distance Graphic Water Stage Register Normal Vertical Range, to 10 feet. Time Scale, 7 Days, 4 Days, or 1 Day. Patented Nov. 19, 1918 and Aug. 19, 1919 Hydro-electric power companies are becoming more and more interested in the utilization of all the power available. This is the natural result of the high cost of fuel and the ever increasing demand for electric power. One of the pressing power questions of today is, "How much water is being wasted over the dam?" Modern hydraulic practice has demanded a precise and rugged instrument which can be depended upon to accurately record all the fluctuations in the level of bodies of water used for commercial purposes. Instead of mailing, telephoning or telegraphing readings thus made, it has been found more con- venient and economical to use a register which records or indicates in the central office the fluctuations of the level of a distant body of water. If the company has an accurate record of the waste water from hour to hour and from month to month, it is able to estimate the amount of secondary power which may be profitably developed and sold, provided there is a market. The infor- mation may be obtained by stationing a gauge reader at the dam, but this method is either costly or inaccurate, usually both. Gurley Registers are being used more and more for this class of work. The Gurley Long Distance Graphic Register not only furnishes a record from which future additions are planned, but it enables plant superintendents to control efficiently the operation of existing plants. The registers may be used by city water works superin- tendents to indicate at a glance how high the water is in the city reservoirs. Similarly, railroad and irrigation engineers may determine the height of the water in distant reservoirs and thus use or replenish the supply advantageously. 120 W. & L. E. GURLEY, TROY, NEW YORK TYPE OF RECORD The hydrograph or curve recording the stage and time is continuous over seven days and presents graphically all of the fluctations of stage and their time relations. These are shown at a glance by the curve, which is a picture record of conditions. The advantages of this type of record are readily recognized. The following vertical scales can be furnished: to 1 foot, to 5 feet, to 15 feet, to r/2 feet, to 6 feet, to 20 feet, to 2 feet, to 8 feet, to V/2 meters, to 3 feet, to 10 feet, to 3 meters, to 4 feet, to 12 feet, A time scale of 1 day, 4 days, or 7 days can be furnished. As the record of stage is made around the cylinder, there is no limit to the number of revolutions possible, and hence to the range of stage. Therefore, it is advisable to use as low a range as possible and obtain a more accurate reading of the water stage. If occasionally the water stage is above the nominal range of the register, no trouble will be experienced in reading and recording the water level. THE SIMPLICITY OF THE OUTFIT The outfit consists of a float-operated Sender located on the river, lake, canal, reservoir, or harbor in question, and elec- trically connected to a Graphic Register having a special Receiving Attachment. If desired, the Sender may operate any number of Registers and Indicators. The simplicity of the construction of these units makes them very easy to install and insures satisfactory operation. The advantages of Register No. 637 are the same as those given under Registers Nos. 633 and 636 on pages 102 to 104. WATER STAGE REGISTERS 121 THE LONG DISTANCE SENDER The No. 638 Sender, located at the point where the water level is to be measured, is operated by a float, 20" in diameter, and a counterweight. The float should be surrounded by a stilling box to protect it from either waves or surges. The Sender is equipped with two electrical contacts, one of which closes for a fraction of a second every time the water rises 1/20 of a foot, the other, when the float falls 1/20 of a foot. These contacts are so designed that it is impossible for them to stick FIG. 56. No. 638 Float Operated Sender, for Long Distance Graphic Register. and keep the circuit closed, thus interfering with the further operation of the instrument. They were developed in the Gurley Factory, and have been subjected to tens of thousands of tests with heavy load, and up to 250 volts, without any failure or even a sign of deterioration. As stated above, one Sender will operate several Registers, several Indicators, or a combination of one or more Registers and Indicators. 122 W. & L. E. GURLEY, TROY, NEW YORK THE LONG DISTANCE REGISTER The No. 637 Register consists of a Gurley No. 633 Graphic Register equipped with magnets to operate the drum. This Register which is the result of years of experience in manu- facturing water stage registers is equipped with a high grade chronometer, strengthened with specially designed bearings. This clock revolves two screws which carry a pencil carriage along the top of a horizontal drum on which the record is made ; it is adjusted in the ordinary manner to record standard time. Attention is called to the fact that, in using curves for calculation FIG. 57. No. 637 Long Distance Graphic Water Stage Register. of quantity of water discharged, the time scale is just as impor- tant as the elevation scale; consequently the Gurley clock mechanism is designed and manufactured with great care. Instead of being directly connected to the float, as in the No. 633 Register, the drum of the No. 637 Long Distance Register is revolved by two sets of magnets operating a ratchet wheel, in one direction when the water is rising, and in the reverse direction, when falling. These magnets are energized when- ever the circut is closed by the operation of the No. 638 Sender. The operating arms which are attached to the magnet armatures WATER STAGE REGISTERS 123 turn the ratchet wheel one notch each time either magnet is energized. These arms also carry interlocking stops which positively prevent the wheel from turning more than one notch, until the magnet is released and ready for the next step. The rear end of the drum carries a dial and pointer, so that the water stage may be read directly without looking at the chart. THE CONSTRUCTION OF NO. 637 LONG DISTANCE REGISTER The base (1) supports the mechanism of the register. An extra heavy eight-day clock (2) is geared to two time screws (3), which are supported at each end as shown. The clock has two large driving springs and has jeweled bearings on the escapement FIG. 58. No. 637 Long Distance Register shaft. Mounted on two screws is the pencil carriage (4) which moves forward without lost motion, in accord with the turning of the clock shaft, and which can be lifted up from one position on the screws and placed in another, if desired. The pencil (11) is held in the pencil holder (5), which is free to move vertically in a cylinder (6) projecting from the upper side of the base of the carriage (4). The pencil holder (5) is set and the pencil clamped with a screw (25), so that the weight of the pencil and holder presses down against the paper. 124 W. & L. E. GURLEY, TROY, NEW YORK The record cylinder (8), on which the paper is placed, is supported at each end as shown. When the magnets (29) are energized by the Sender, the armatures (27) are moved downward and they revolve the ratchet wheel (28) which is attached to ratchet wheel shaft (26) and revolves in eccentric bushing (24). The gear (20) is clamped to the sprocket wheel shaft by the nut (15). The gear (21) is clamped to the cylinder (8) by three small screws. The bolt (13) is used to lock the cylinder, while changing the record sheet. Extending across the face of the record cylinder (8) is a slot (12) which indicates the point of zero gage height on the record cylinder. THE LONG DISTANCE INDICATOR Where an indication of some distant water level is desired and a record is unnecessary, the need is met by the No. 639 Long Distance Water Stage Indicator, operated by the No. 638 FIG. 59. No. 639 Indicator, front and rear views. Sender. A moving Pointer indicating on a dial 12 inches in diameter, is operated by electro-magnets and a ratchet wheel, in the same manner as the Long Distance Register. This dial shows at any instant the height of the water at the distant gage house. One or more of these Indicators may be put on the same circuit with a Register. In many instances, it is desirable to have an Indicator in the power plant for the information of the operator, while the Register is placed in the office of the chief engineer, where the records are kept and studied. WATER STAGE REGISTERS 125 THE ELECTRICAL CIRCUIT FOR THE LONG DISTANCE OUTFIT The circuits necessary to connect the Sender and Receiver may consist either of 3 wires or 2 wires and a "ground" return. A satisfactory circuit may be obtained by leasing a private telephone line of 2 wires. The current required to operate the receiver is 0.1 ampere and this flows through the line for only a fraction of a second when the contact is made. At all other times the circuits are open. The resistance of the coils is 40 ohms. The power may be supplied by dry cells or storage batteries. For long distances it is better to take it from a 110 volt D. C. power or storage battery line, where the current is uninterrupted. A lamp placed in the circuit will cut down the current to the proper amount, that is, 0.1 ampere. The power may be connected into the circuit at either the Sender or Receiver end, or in case of an all metallic circuit, at any point in the line. By the proper use of condensers, any number of private telephones may be used on the same line without interfering with the operation of the instruments. FIG. GO. Wiring Diagram showing the method generally used in installing Gurley Long Distance Registers. 126 W. & L. E. GURLEY, TROY, NEW YORK Cosic/erjser l\ Ca//be//s Condenser D Call be/ /s L oca/ bat fere/ &r-/c/g/ng wa// fe/ephone, >ar; /6OO 0/7/77 rsnger m 'i////- r-|__J SOO ohms p?L_l OOo^s77S /m/zec/o/Tce /ds ?//-/-ec/ Ct//-/-es?/ /Yec//'/-a/ w//-0 L/ve w/re //O FIG. 61. Wiring Diagram of the installation of a Gurley Long Distance Register at Topeka, Kansas. WATER STAGE REGISTERS 127 INSTALLATION AND OPERATION OF THE GURLEY LONG DISTANCE OUTFIT The Stilling Box. The minimum dimension of the stilling box is 24". In order to install a hook gage and a heating unit, the stilling box should be 36" square, and a larger size is pref- erable. Build the stilling box down to the bottom of the water to prevent waves from agitating the float. A 2" lever throttle valve should be placed in the side of the box below the lowest stage. By regulating this, surges in the stilling box can be prevented. To lay out the Table and Floor. The dimensions to be used are given in Figs. 62 and 63. Carefully locate holes (1) and (2) in the floor so that neither the float nor the counter- weight will touch the sides of the stilling box at any stage of . *** x e 5, 'JK ( a. r L_ ,* S 5 b" C-I ^ if: o2. 6 SM as; /6OO O/4/77 r/nger mu/i/'/- p/e //O yo/fs Wiring Diagram of the Installation of a Gurley Long Distance Recording Outfit at Topeka, Kansas W. & L. E. GURLEY, TROY, NEW YORK Gurley Experimental Gaging Station Experimental Gaging Station on the Poestenkill, Troy, N. Y., used by W. & L. E. Gurley in connection with the development of water stage registers and other types of hydraulic equipment. The wooden shelter covers a concrete well and provides ample light and air by means of three windows, a door and two ventilators. The Gurley Long Distance Sender is shown installed in this structure ; this Sender is connected by a telephone line to the Long Distance Recorder at the Gurley factory, about two miles distant. Engineers visiting Troy will be taken to inspect this gaging station, upon request. 10 Price List Gurley Hydraulic Engineering Instruments Price iis supersedes all previous editions. All prices are subject to change without notice. Revised to January 15th, 1922 W. & L. E. GURLEY, Makers Established 1845 TROY, N. Y., U. S. A. 2 W. & L. E. GURLEY, TROY, N. Y. Guarantee ALL INSTRUMENTS OF OUR OWN MAKE are examined and tested before being shipped, and are sent to the purchaser adjusted, ready for immediate use. When purchased directly of us, they are warranted correct in all their parts we agreeing in the event of any original defect appearing after reasonable use, to repair or replace with new and perfect instruments, promptly at our own cost, express charges included ; or we will refund the money and the express charges paid by the purchaser. It sometimes happens, in a business as large and widely extended as ours, that instruments reach our customers in bad condition, owing to careless transportation or to defects escaping the closest scrutiny of our inspectors. We consider the retention of such instruments by the pur- chaser an injury very much greater to us than to himself. We also consider that a sale is not completed until the purchaser is satisfied in every detail. Ordering In ordering, ALWAYS GIVE THE CATALOGUE NUMBER. If full particulars concerning each item accompany the order, delay will often be avoided, as it will probably be unnecessary for us to write you. If no shipping directions are given, we will always ship by the quick- est and safest method. WE MAKE NO CHARGE FOR PACKING BOXES OR PACKING, and our instru- ments are delivered F. O. B. Troy, N. Y., to the express company or freight house. CHARGES FOR TRANSPORTATION ARE IN ALL CASES TO BE PAID BY THE PURCHASER, we guaranteeing the safe arrival of our goods at the destination indicated at the time of shipment. Terms of Payment Terms of payment are uniformly cash and we have but one price, whether ordered in person or by mail. Our prices are as low as can be made for instruments of first quality. REMITTANCES may be made by bank draft. Express or Post Office money order, payable to our order, at Troy, N. Y. When goods are shipped C. O. D., a remittance of 25% of the total amount should ac- company the order. Foreign Shipments Instruments packed for foreign shipment which are to have ocean pass- age are wrapped in waterproof material and enclosed in strong packing boxes which are strengthened and protected by special band wire. THE CASH FOR ALL ORDERS FOR FOREIGN SHIPMENTS BY STEAMSHIP MUST, IN EVERY CASE, ACCOMPANY THE ORDER ; and if it is desired that we attend to the shipment of the instruments, the remittance must be made ten per cent, more than the catalogue price of the instruments if the order amounts to less than $300 or eight per cent, more than catalogue price if the order amounts to from $300 to $500 ; or six per cent, more than cata- logue price if the order amounts to from $500 to $1,000. This extra remittance is to cover or apply on the cost of shipping charges, freight and insurance, which must always be paid in advance on all shipments. If the amount remitted is more than enough to cover these expenses, the balance will be refunded to the purchaser with the receipted bill and bill of lading, unless we are directed to hold it to his credit. REMITTANCES must be made in funds current in New York, or by bank draft on New York City or London, England. Such drafts can be purchased in any of the large cities of the different countries. PRICE LIST Gurley Current Meters Acoustic Current Meter Price No. Oil) Acoustic Current Meter, indicating each 10th revolution, equipped with rubber tube, ear piece and connection ; also two lengths of flush-jointed wading rod, graduated to measure 4 ft. from plane of bucket wheel. Wooden case with lock and strap and including accessories of oil can, wrench, screw driver and pivot bearing (See page 21) $66.00 Accessories for No. 616 Wading Rod, flush-jointed and graduated, per 2 ft. length Canvas Case for two, three or four lengths of Rod Time Recorder, or Stop Watch. No. 619, open face nickle case, stem winder, with fly-back attachment for start- ing and stopping. Registering minutes, seconds and fifths of seconds 10.00 Electric Current Meters No. 623 E'lectric Current Meter with two interchangeable commu- tator boxes, one indicating each revolution and the other indicating each fifth revolution of_the bucket wheel, Covert Yoke, telephone receiver, dry battery, 20 ft. of cable, 10 Ib. lead weight and weight hanger. All packed in wooden box with lock, hooks and strap and including accessories of oil can, wrench, screw driver, extra pivot bearing, binding screws and nipple (see page 22) 110.00 No. 617 Electric Current Meter. This is like No. 623, except that it has only one commutator box indicating each revo- lution of the bucket wheel (see page 22) 93.50 No. 621 Electric Current Meter. This is like No. 623, except that it has only one commutator box indicating each fifth revolution of the bucket wheel (see page 22) 93.50 Accessories for Current Meters Nos. 617, 621 and 623 Extra Cable, per foot .05 Extra Dry Cell Battery __ .35 Extra Lead Weight, 10 lbs.__ ___ 5.00 Extra Lead Weight, 15 Ibs 6.25 Time Recorder, or Stop Watch, No. 619, as described above under Meter No. G1G__ 10.00 W. & L. E. GURLEY, TROY, N. Y. Accessories for Current Meters Nos. 617, 621 and 623 (Continued) \V:uling Hods, flush-jointed and graduated, for use with double-end Hanger, per 2 ft. length _ $.>.50 Wading Rods, flush-jointed, 4 sections, graduated to measure 8 feet from plane of bucket wheel, @ $3.50 per section 14. Leather Case for rods, base and Imiiger ._ . !.'*>.( MI Canvas Case for rods, base and hanger 4.50 Electric Register, No. G09, as described on page 25 25.00 Special Carrying Case of fibre, for Current Meters Nos. 017. 021 or 023, (see page 20) __ 21.00 If the Special Fibre Case is furnished, instead of the regular wooden box, the extra cost is 11.00 Record Sheets for Current Meter Notes Form No. H-325 Discharge Measurement General Data (see page 54), per 100 sheets 2.00 Form No. H-326 Current Meter Notes fcr open Streams (see page 55), per 100 sheets 2.00 Form No. H-327 Current Meter Notes for Ice-covered Streams (see page GO), per 100 sheets. _ 2.00 Suitable Canvas-covered Loose-leaf Binder .7-" Note : In practice, about one sheet of Form No. H-325 is used to every three sheets of Forms Nos. H-320 and H-327. Any quantity will be supplied and sample sheets will be submitted upon request. When ordering specify by form numbers. River Discharge" A complete and detailed description of both the use of the Current Meter, Hook Gage and Water Stage Register, and the collection and use of data in regard to the flow of streams. River Discharge, by J. C. Hoyt and N. C. Grover, Hydraulic Engineers. United States Geological Survey. Cloth, 210 pages, 6 x 9, 39 figures, 11 plates. Fifth Edition. Price, postpaid, $2.50 Individual Current Meter Rating Tables For Meters No. 616, 617 or 621 10.00 For Meter No. 623 20.00 Allow from 10 days to two weeks time. See page 36. Gurley Hook Gage No. 028 Hook Gage (see page 73) __ 25.00 PRICE LIST Parts for Current Meter No. 616 I When ordering parts, always specify shop numbers Sliop No. Name of Part Price 1 Yoke $13.25 2 Connecting Tube 3.85 3 Commutator Box 6.00 10 Frame Nut 1.40 95 Wrench .__ 1.25 115 Bucket Wheel . .__ 13.25 238 Screw Driver . .35 239 Oil Can ___ .50 243 Pivot with Lock Nut _ 1.40 Shop No. Name of Part Price 249 Bucket Nut and Raising Nut _ $1.65 252 Goose Neck 6.50 253 Gear, Gear Holder, Grass- hopper, etc. 6.50 254 Commutator Box Cap and Diaphragm combined __ 2.75 255 Shaft 2.T5 Grasshopper 1.40 Wooden Box . 9.30 W. & L. E. GURLEY, TROY, N. Y. Parts for Current Meters Nos. 617, 621 and 623 PART NUMBERS CURRENT METER No*.617,621,6Z3 & 624 W.&L.E.GURLEY, TROY, N.Y. When ordering parts, always specify shop numbers Shop No. Name of Part Price 10 Frame Nut .$1.40 75 Yoke 18.75 85 Worm and Shaft 2.75 86 Plain Shaft 1.40 87 Worm __. 1.40 88 Eccentric . .85 95 Wrench __. 1.25 103 Weight Hanger _ 2.75 104 Weight Hanger Screw __ .85 115 Bucket Wheel 13.25 166 Weight Pin for 10 Ib. and 15 Ib. Weights .55 184 Frame Cap .85 188 Binding Post Complete _ 1.40 195 Vane or Tail Piece complete 10.00 238 Small Screw Driver ___ .35 239 Oil Can .50 243 Pivot with Lock Nut - 1.40 Shop No. Name of Part Price 246 Single Revolution Com- mutator Box complete $16.50 247 Penta or Five Revolution Commutator Box com plete 16.50 248 Shaft and Eccentric complete 2.25 249 Bucket Nut and Raising Nut 1.65 274 Connector .50 278 Balance Weight 1.10 78 Cap for Commutator Box .85 109 Set Screw, 6 x 32 .05 Telephone Receiver ___ 4.00 Dry Battery .35 Cable with Terminals __ 3.00 Head Band 2.00 Carrying Box (wood) . 30.00 PRICE LIST Gurley Printing Water Stage Register No. 630 No. 630 Printing Water Stage Register, range 3G.99 ft. without repeating; prints at 15-ininute intervals; complete with paper ribbon and carbon paper for one year's record ; metal protecting cover with lock, float and counter- weight, 2 weights, 40 ft. phosphor bronze tape, wrench, 2 screw drivers, bottle of watch oil and oil pump. Shipping weight 2 boxes, about 275 Ibs. (see page 87) $385,00 Register No. 630 can be modified to print at 30 minute, or CO minute intervals, if specified, without extra charge. Paper Ribbon for No. G30 Register, per roll _^__ 2.00 Carbon Ribbon for No. 630 Register, per roll _ ___ 3.25 Watch Oil, small bottle _.._ .75 No. 632 Tape Reel, for use with No. 630 Register (see page 91) 27.50 Gurley Graphic Registers Nos. 633 and 636 No. 633 Graphic Water Stage Register, spring-driven clock : range, to 10 feet; time scale, 7 days; complete with metal cover, 10 record sheets, float, counterweight, 20 ft. of phosphor bronze tape, and bottle of clock oil. Shipping weight about 75 Ibs. (see page 104) 145.00 No. 636 Graphic Water Stage Register, weight-driven clock ; range, to 10 ft. ; time scale, 7 days ; complete with nietal cover, 10 record sheets, float, counterweight, 20 ft. of phosphor bronze tape, and bottle of clock oil. Shipping weight about 75 Ibs. (see page 107) 145.00 Register No. 633 or Register No. 636 can be modified to give either a 4-day record, or a 1-day record, without extra charge, (see page 110). If extra time screws, pencil carriages and gears are re- quired, there will be an additional charge as follows : 2 Time Screws and Pencil Carriage for 4-Day Register 13.75 2 Time Screws and Pencil Carriage for 1-Day Register 17.00 1 Set of Gears, for any range 4.50 Record Sheets for No. 633 or No. 636 Register, each .05 Clock Oil, small bottle .75 Gurley Graphic Registers Nos. 634 and 634-A No. 634 Graphic Water Stage Register, range to 1 foot, natural scale ; time scale, 7 days ; complete with metal cover, 10 record sheets, float, counterweight, and 10 ft. of phos- phor bronze tape. Shipping weight about 75 Ibs. 95.00 Register No. 634 can be modified to give either a 4-day record, or a 1-day record, without extra charge. If an extra pencil carriage and set of time screws are required, there will be an additional charge as follows : For the 4-Day Register _ .__ 13.75 For the 1-Day Register _ .__ 17.00 No. 634-A Graphic Water Stage Register ; range to 2 feet ; time scale, 7 days ; complete with metal cover, 10 record sheets, float, counterweight and about 10 ft. of phos- phor bronze tape. Shipping weight about 75 Ibs. 110.00 The sprocket wheel on this register is 2 ft. in circumference, instead of 1 foot as on No. 634. 8 W. & L. E. GURLEY, TROY, N. Y. Gurley Graphic Registers Nos. 634 and 634-A (Continued) Register No. (5:54- A can be mortified to give either a 4-day record, or a 1-day record, without extra charge. If an extra pencil carriage and set of time screws are re- quired, there will be an additional charge as follows : For the 4-Day Register _ _ $1:5.7:. For the 1-Day Register 17. w Record Sheets for No. 634 Register, each .05 Record Sheets for No. 634-A Register, each . . Clock Oil, in small bottle .75 Gurley Indicating Gage No. 639-A Indicating Gage, complete with float and counterweight (see page 130) . 55.00 Gurley Long Distance Water Stage Register Outfits The cost installing the Gurley Long Distance Recorder depends very largely on local conditions and our Engineering Department will gladly cooperate in suggesting how local problems may best be solved. The prices of sending and Recording apparatus are as follows: No. 638-A Long Distance Recording Outfit, consisting of a No. <;:;s Sender and a No. 037 Register . 385.00 No. 638-B Long Distance Indicating Outfit, consisting of a No. 638 Sender and a No. 639 Indicator _ - 265.00 No. 638-C Long Distance Recording and Indicating Outfit, consist- ing of a No. 638 Sender, a No. 637 Register, and a No. 639 Indicator _ - 540.00 Separate instruments may be had for the following prices : No. 637 Register, complete with glass cover, 10 extra record sheets, bottle of clock oil. Shipping weight about 100 Ibs. 27r.(K No. 638 Sender, complete with metal cover, lock, 20 inch float, counterweight, 20 ft. phosphor bronze tape, 2 guide pulleys, bottle of clock oil. Shipping weight about 75 Ibs. 110.00 No. 639 Indicator, complete with glass cover, and bottle of clock oil. Shipping weight about 15 Ibs. 155.00 Gurley Private Cable Code Cable Address: "Gurley, Troy. N. Y." Use Western Union, Five-Letter Edition ; Bentley's ; Lieber's ; or A. B. C.-oth Edition, Codes Cat. No. 609 612 614 615 616 (117 619 621 623 628 Description Code Cat. Word No. Electric Register Acrub Dry Battery Actib Insulated Copper Wire Acush Telephone Receiver Acvan Current Meter Outfit Acvod Current Meter Outfit Acwid Time Recorder Adaf t Current Meter Outfit Adbel Current Meter Outfit Adbot Hook Gage Abcek Printing Water Stage Register. .Anvel Tape Reel Anwat Description Code Word 633 Graphic Water Stage Register .Abcet 634 Graphic Water Stage Register .Abcev 634-A Graphic Water Stage Register .Abcic 636 Graphic Water Stage Register .Abcif 637 Long Distance Register Abeik 638 Long Distance Sender A belt 639 Long Distance Indicator Abein 639-A Indicating Gage Abeir 638-A Long Distance Recording Outfit. Abeiv 638-B Long Distance Indicating Outfit. Abeix 638-C Long Distance Recording and Indicating Outfit Abeji W. & L. E. GURLE" Gurley Experirm Engineering T-ibrarv UNIVERSITY OF CAUFORNIA UBRARY Experimental Gaging Station on the connection with the development of water stai The wooden shelter covers a concrete well windows, a door and two ventilators. The Gi structure ; this Sender is connected by a telephj factory, about two miles distant. Engineers visiting Troy will be taken to MWWNMMHH