A STUDY OF RECENT DEVELOPMENTS AND INVENTIONS IN ENGINEERING INSTRUMENTS Thai: for III. Dean. of I. S. MICHIGAN STATE COLLEGE Paul W. Hoynigor I948 This]: _ C./ SUPP! '3' Nagy NIH: LJWIHL WA KOF BOOK A STUDY OF RECENT DEVELOPMENTS AND INVENTIONS IN ENGINEERING’INSIRUMENTS A Thesis Submitted to The Faculty of MICHIGAN‘STATE COLLEGE OF AGRICULTURE AND.APPLIED SCIENCE by Paul W. Heyniger Candidate for the Degree of Batchelor of Science June 1948 \. HE-UI: PREFACE This Thesis is submitted to the faculty of Michigan State College as one of the requirements for a B. S. De- gree in Civil Engineering.' At this time,I Iish to express my appreciation to c. M. Cade, Professor of Civil Engineering at Michigan State Collegeafor his assistance throughout the course and to the manufacturers,vhose products are represented, for their help by freely giving of the data used in this paper. In preparing the laterial used in this thesis, it was the authors at: to point out new develop-ants on existing instruments and recent inventions or engineer- ing equipment used principally by the Civil Engineer. 20 6052 TAEEE OF CONTENTS Chapter One Page Introduction B. Drafting Equipment ----------------------- 13 Chapter Two Telescopic Inprovenents A. Glass Reticles .......................... -32 B. Coated Lenses .......................... --J.B Chapter three The Tilting Level- ............................ -33 Chapter rear The First One-Second.Anerican Optical 28 “00d011 ‘6- -------------------------- e- --------- Chapter rive Chapter Six The Latest Type Altineter ----- - ................ 5.5 TABLE OF CONTENTS , Chapter Seven Page The Most Recent Drafting Machine ........... -39.--- Chapter Eight Chapter Nine SmOnnB By Radar ....... - ------------------ In”.-- Chapter Ten Conclusion ------------ - ----- -. ............. ”"39.-- CHAPTER ONE INTRODUCTION A. Surveying Instruments. There are numerous reasons why we should consider new developments and inventions in engineer equipment at the present time. World War Three gave an impetus to develOpment and invention in all phases of science and engineering which produced many new products and techniques which a great number of established and graduating engineers are not familiar with. These new developments and inventions save time and thereby reduce field and office costs. They are more accur- ate making possible the performance of a higher order of surveying and they are more flexible which means the equip- ment and techniques can be adapted to more different types of Jobs. The study of modern engineers equipment and instruments is more completely understood if the evolution and invention of engineers equipment is traced thru history. It is probable that surveying instruments had their origin in ancient Egypt. A plan of the villa of a great Egyptian noble was found in a Theban tomb of the eighteenth dynasty. A tomb of a certain Manna of Thebes contains a representation of two chairmen surveying a corn field and in Ptolemic and Roman papyri measurements of plots of land are described. The dimensions of the great Pyramids clearly illustrates that the early Egyptians had some engineer equipment of considerable accuracy. The Romans invented the Groma which consisted of two of two horiz- pairs of plumb lines suspended from the ends to one an- ontal rods which were fastened at right angles at right other and which enabled them to lay out lines angles to one another. The Romans used ten foot rods for measuring distances. inches The foot, at that time, measuring 13.2 of our present for align- The Romans also used a crude type of plane table ing their roads. ‘ the The Greeks used a form of log line for recording while making distances from point to point along the coast Gulf in their slow voyage from the Indus to the Persian 300 8.0. 1600 B.C Compasses were used by the Chinese as early as by making use of the lodestone. Greek The Plani spheric Astrolobe was invented by the Bipparchus (150Tfi.c.) and consisted of an evenly balanced and pro- circle or disk of metal or wood, hung by a ring vided with a rotatable alidade or diametral rule with sights, the altitud- turning within a circle of degrees Jfor measuring es of the sun and stars. Plane tables were in use in Europe in the Sixteenth Century. The various instruments and equipment used by the engineer fall into five main classes; those for, (1) Measuring distance (2) Determining direction (3) Determining horizontal lines. (4) Measuring angles (5)1Miscelaneous work Chains, tapes, wooden and metallic rods are used for :measuring distances. The chain is of two types ,the Gunter and the Engineers. The Gunter chain was invented by Ed- :lnnd Gunter, an.English engineer, in 1620 and is 66 feet long divided into 100 links each of which is 7.92 inches long. These links are composed of heavy steel wire and each includesJat every tenth linkJa numbered brass tag, ihile at each end of the chain is a handle. This chain is need in public land surveys which do not require great accuracy. The Engineers chain is composed of 100 links each of which is one foot long. This chain is also used only for rough.measuring. Engineer tapes are usually 100 to 200 feet long and made of thin one quarter inch ribbons of steel or nickel- steel alloy which has a small temperature coefficient and is known as invar metal. The feet and subdivisions are etched on these tapes. Direction can be measured by the surveyors compass which consists essentially of two uprights having verti- cal slits to give a line of sight and which are attached to horizontal graduated circle at the center of which is mounted a magnetic needle free to move, the whole being supported by devices for leveling. This surveyors compass is not used for accurate work. The prismatic compass is a hand instrument with a glass prism so arranged that the needle is read while taking a sight. The Locke level has no telescOpe but is simply a metal tube with a plain glass cover at each end and a spirit level on top. The bubble and cross wire ( re- flected in a prism ) are in the left half and the land- scape in the right half of the field of view. A point on the landscape is level with the observers eye when the reflected image of the bubble is at the center of its tube. The Engineers Wye level is most commonly used to determine horizontal lines. This instrmment consists of a telescope with cross hairs to determine the line of sight clamped in Yeshaped uprights rising from a bar and carry- ing a spirit level and resting on a vertical pivot re- 'volving in a socket in the plate which fastens the instru- :ment to its tripod or other support. Leveling screws per- ndt the adjustment of the Spirit level bar to a horizontal position, and when the axis of the telescope is parallel to this bargthe line of sight . is horizontal. A Bumpy level is similar havtng asshorter telescope with a wider aperature. The Engineers level rod is graduated to feet and fractions of feet and has a target which is slid up and down to coincide with-the line of sight of the level telescope. The Engineers Transit consists of a telescOpe mount- ed so that it may be rotated about its vertical and hor- izontal axis and it is used for measuring both horizon- tal and vertical angles. In addition it reads distances by use of the stadia wires, determines bearings by the use of the magnetic needle, levels by means of the spirit level attached to the telescope, and does the work of a solar compass by the use of attachments. The vernier of the transit is a scale by which the linear or angular magnitude can be read with a much greater degree of accuracy than is possible by mere mechanical division and subdivision, The verniers of the transit are usually of the direct type, which means a vernier whose equal divisions exceeds the corresponding number on the scale. The principle of the vernier formula is derived on the following page. The Theodolite is constructed the same as the tran- sitJhowever the telescope cannot make a complete revolu- tion on the horizontal axis. Theodolites are commonly made larger and more powerful than transits and are mostly used in important triangulation work as Coast and Geodetic Surveys. The Sextant is similarly a telescopic instrument but is used primarily in navigation. Engineers sometimes use the Sextant when angles have to be measured from a boat,as in locating soundings and buoys. The Plane Table is an instrument for making topo- IO‘. D-ER/ VA 770/v IOF VE RN/E R FORM UL A T 1 vi JLx/lngvlv < ,WZED T 8= SPACES ON LIMB v = spa cas ON VERN/ER _ L'- LEAST DASCERNABLE MOVEMENT N: NUMBER OF SPACES a) NV= (xv—z) 3 0/? WM ALSO ‘ N @ L,= s-v SUBSTITUT/NG Q) //v Q) L =—.. ‘SQVN’M'NS __I II graphic surveys and consists of a drafting board mounted on a tripod together with an alidade. The alidade is a telescopic sight line mounted on a vertical support which is attached to a ruler, the edge of which is parallel to the line of sight. The Aneroid Barometer is a hollow metal corrugated box from which the air has been partially eXpelled and which is so thin that it will change shape when the air pressure changes. The movement of the box t0p is comp municated to a spring and then to a series of levers and a link at the end of which a chain is wound around a shaft to which a pointer is fastened. The pointer indicates two scales on the face of the dial.