referring now to fig1 - 20 wherein like numerals refer to similar parts the bobber 20 of fig1 - 6 , and 12 has a support 22 for attachment of the bobber 20 to a conventional fishing pole 24 . the fishing pole 24 may be hand held , or , as shown in fig1 supported on the ice by a two - legged brace 25 which acts with the pole itself as a tripod base for the fishing apparatus comprised of the fishing pole 24 and the bobber 20 . the support 22 has a tip mount 26 for attachment of the support to the tip 28 of the fishing pole 24 . the tip mount 26 may be of any appropriate shape to snugly fit on the tip 28 of the fishing pole 24 , but for the standard cylindrical fishing pole , the tip mount 26 is typically a cylindrical tube . the tip mount 26 fits on the tip 28 of the fishing pole 24 snugly , thereby fixedly attaching the support 22 to the fishing pole 24 . the support 22 has two upright members 30 attached to the tip mount 26 on opposite sides . a collar 32 is pivotally mounted between the upright members 30 of the support 22 . the collar 32 which is preferably a thin metallic or plastic ring , is mounted between the upright members 30 by a pin or , as shown , by two pins 34 running perpendicular to the axis of the collar and rotating freely in holes 36 in the upright members 30 . the bobber 20 has an elongate balance member with a portion having an unvarying exterior profile . the balance member is preferably in the form of a cylindrical tube 38 and is positioned within the annular collar 32 . the outer diameter of the tube 38 is slightly less than the inner diameter of the collar 32 so as to permit adjustable but snug positioning of the tube within the collar . the tube 38 is slidably positionable within the collar 32 which engages and retains the tube 38 . the tube has one closed end 40 which faces towards the tip 28 of the fishing pole 24 and one open end 42 which faces away from the tip . the tube 38 is positioned concentrically within the collar 32 . as shown in fig4 - 6 the hollow interior of the tube defines an internal cylindrical cavity which acts as a cylindrical linear race 44 for a rolling weight 54 . a tubular cap 46 with a closed end 48 and an open end 50 fits snugly and removably over the tube 38 so that the closed end 48 of the cap 46 closes the open end 42 of the tube 38 . the inner diameter of the cap 46 is dimensioned to be slightly larger than the outer diameter of the tube 38 so that the cap 46 may be adjustably positioned on the tube 38 as shown in fig4 - 6 . the cap 46 and the tube 38 together form a closed tubular assembly 52 of adjustable length . a dense , substantially spherical weight 54 runs in the race 44 of the tubular assembly 52 . the weight 54 may be of any sufficiently dense material , such as steel , brass , or lead . as the length of the tubular assembly 52 is adjusted by drawing the cap 46 backwards along the tube 38 the race 44 will extend into the cylindrical interior of the cap 46 . a rigid hollow cylindrical member 56 is attached to the tube 38 beneath the closed end 40 . the hollow member 56 is of smaller diameter than the tube 38 and has a central cavity 58 adapted to receive a centrally threaded fishing line 64 . the hollow member 56 extends outward a specified distance from the tube 38 which may be any desirable length but is preferably on the order of 2 to 4 inches . to facilitate threading of the hollow member 56 an angled cutoff 60 is optionally provided at the entrance to the hollow member 56 . a brightly colored , preferably fluorescent signal coating 62 may be applied to the extended end of the hollow member 56 to increase its visability . as shown in fig1 the bobber 20 is mounted on the tip 28 of the pole 24 with the tip 28 inserted into the tip mount 26 so that the tube 38 of the bobber 20 is located above the pole 24 . a length of fishing line 64 is drawn from the reel 66 , extended under the tube 38 and threaded through the hollow member 56 . once the line 64 is threaded through the bobber 20 , the lure 68 may be attached to the end of the line 64 and the line dropped into a hole cut through the ice 70 , as shown is fig 1 , so that the lure 68 will be suspended in the water 72 a desired distance beneath the ice 70 . the combined weight of the bobber 20 , the lure 68 , and portions of the fishing line 64 is supported by the pins 34 mounted in the holes 36 of the upright members 30 of the tip mount 26 . if there is a balance between the weights forward and aft of the pivot point 74 the bobber will orient itself roughly horizontally and will be in a condition to effectively signal a bite on the lure 68 . the bobber 20 may be adjusted in two ways to obtain the desired balance . the tube 38 may be moved within the collar 32 and the cap 46 may be adjusted on the tube 38 . different configurations of the bobber 20 will accommodate a variety of lures 68 of different weights or differing lengths of fishing line 64 . the primary means of adjusting the bobber 20 for balance is movement of the tube 38 within the collar 32 . moving the tube 38 forward in the collar 32 increases the weight forward of the pivot point 74 and decreases the weight aft of the pivot point 74 . fig4 - 6 show examples of possible positions of the tube 38 within the collar 32 . fig6 shows the tube 38 pushed far forward to accommodate a lightweight lure or a short length of line . fig5 shows the tube 38 pulled back to balance a heavy lure or a long length of line . fig4 shows the tube 38 in an intermediate position in the collar 32 to accommodate an intermediate weight . the tube 38 may be positioned within the collar 32 at any position along its length to accommodate a wide range of weights to obtain a very accurate balance . between the extremes of position the tube is infinitely adjustable within the collar . if additional adjustment is required , as where a heavy lure , line , or sinker are employed while fishing at greater depths , the cap 46 may be pulled back on the tube 38 , as shown in fig5 to extend the length of the race 44 and allow the weight 54 to assert a balancing force at a greater distance from the pivot point 74 . to adjust for a lighter lure beyond moving the tube 38 forward in the collar 32 the cap 46 may be pushed inward on the tube 38 to decrease the length of the race 44 . when an equilibrium position is reached the weight 54 will be adjacent the closed end 48 of the cap 46 and the lure 68 will be maintained at a substantially constant depth . further adjustment is possible by removing the cap and replacing the weight 54 with a weight of more or less dense material . the weight 54 may also be eliminated , in which case adjustment will be solely by positioning the tube 38 within the collar . when a fish 76 takes the lure 68 , a downward force is applied by the fishing line 64 to the bobber 20 . this force will cause the tube 38 to tilt forward as shown in fig6 and 12 . when the race 44 is inclined forwardly , the weight 54 will roll forward . the farther forward that the weight 54 rolls , the more unbalanced the bobber 20 will become . once unbalanced , the weight 54 will roll all the way to the end of the race 44 until it strikes the closed end 40 of the tube 38 . when in this unbalanced position , the hollow member 56 will point downward with the bobber 20 in a vertically inclined configuration . the bright signal coating 62 on the hollow member 56 makes it easy for an angler to observe that the bobber 20 is in its unbalanced state . the angler may then return to the fishing pole and attend to the capture of the fish . because of the bright color of the signal coating 62 , the hollow member 56 should be visible by twilight or moonlight . an audible signal is also provided to the nearby angler . the motion of the weight 54 rolling in the race 44 and the impact of the weight against the closed end 40 produces a faint but perceptible noise that serves to alert the angler , provided he is sufficiently close to the pole , that a fish has taken the line . for dark nighttime fishing the bobber 20 may be modified to provide a luminescent signal to the angler . such a modified bobber is shown in cross section in fig7 . the illuminated bobber 80 has a light - emitting diode 82 mounted outside the closed end 40 of the tube 38 . the weight 54 of this embodiment must be fabricated of an electrically conductive material , such as copper or steel , or be coated with sufficient electrically conductive material to carry the current necessary to light the light - emiting diode 82 . a battery lead 84 and a ground lead 86 pass through the closed end 40 into the interior of the tube 38 . a battery 88 is located within the tube and has the appropriate current and voltage capacities to illuminate the light - emitting diode . the battery has a positive terminal 90 electrically connected to the battery lead 84 and anegative terminal 92 electrically connected to a negative contact 94 . a positive contact 96 is electrically connected to the ground lead 86 and is positioned within the tube spaced across the diameter of the tube from the negative contact 94 . the contacts 94 , 96 are fixedly positioned within the tube so that when the weight 54 rolls in the race 44 to its closest proximity to the closed end 40 the electrically conductive weight 54 will touch both contacts 94 , 96 , completing an electrical circuit and lighting the diode 82 . in the illuminated bobber 80 , when a fish tugs on the line , unbalancing the bobber 80 , the weight will roll forward to the closed end 40 of the tube causing an electrical connection and lighting the light - emitting diode . the light of the diode 82 serves as a visual signal to the angler that a fish has taken the line . an alternative embodiment of the bobber of this invention is shown in fig8 - 11 and 13 . the flexible bobber 100 has a cylindrical attachment tube 102 adapted for attachment to the tip of a fishing pole 28 with an adhesive such as tape 104 . the tape 104 may be duct tape , electrician &# 39 ; s tape , shrink tape or any other suitably adhesive and water - resistant tape . the attachment tube 102 is attached to the fishing pole 24 with a portion 108 extending outwardly beyond the end of the tip 28 of the pole . a cylindrical flexible tube 106 is snugly fitted over this extending portion 108 . the flexible tube 106 may be fabricated of natural or synthetic rubber or any appropriately flexible material . a rigid cylindrical line tube 110 of substantially the same diameter as the attachment tube 102 is snugly fitted within the flexible tube 106 in spaced relation to the attachment tube . the resilience of the flexible tube 106 allows the adjustable positioning of the line tube so as to be in substantial alignment with the attachment tube 102 when the flexible tube 106 is undeflected . the line tube 110 has a coating of bright coloring 112 which may be in the form of a fluorescent strip of adhesive tape , an enamel coating , or a painted or sprayed - on coating of paint . the attachment tube 102 , the flexible tube 106 , and the line tube 110 all have an inner diameter that will allow the unrestricted threading of the fishing line through the tubes . the bobber 100 is mounted on the fishing pole 24 , as shown in fig1 , and the fishing line 64 is threaded through the tubes 102 , 106 , 110 . a lure 68 is attached to the end of the line and lowered into the water . when a fish takes hold of the lure 68 , it will assert a downward force on the line with the result that the line tube 110 will be pulled downward . the flexible tube 106 allows the line tube 110 to rotate about the end of the attachment tube 102 until it is in a roughly vertical position as shown in fig1 . this attitude of the line tube 110 serves to signal visually to the angler that a fish has taken the lure 68 . depending on the weight of the lure and the fishing line , a flexible tube 106 of greater or lesser stiffness may be used so that the line tube 110 remains substantially undeflected until a fish bites . when changing lures , the angler may simply replace one flexible tube with another of the desired stiffness characteristics . it should be noted that the rigid parts of the bobber may be fabricated of metal such as brass , steel , aluminium , or zinc ; or of a suitable plastic material . the support 22 may be fabricated with only one , suitably rigid , upright member , instead of the two upright members 30 of the preferred embodiment . furthermore , if desired the weight 54 and cap 46 may be omitted and the tube 38 fabricated as a solid or hollow cylindrical balance member . the adjustable balance of the bobber would then be achieved entirely by moving the cylinder within the collar 32 . although the cylindrical shape of the bobber facilitates steadiness of the bobber 220 in windy conditions , the tubular assembly may have an exterior profile that is not circular , so long as it has a portion of a constant exterior profile to allow the slidable adjustment of the tubular assembly within the collar . the collar as well can be other than a cylinder so long as its interior profile matches the exterior profile of the portion of the elongated balance member or tubular assembly . the support may also be adapted to be screwed to an upwardly extending line guide attached to the tip of the pole . it should also be noted that the pivot point 74 may be located at any desired position perpendicular to the axis of the collar and the tube -- either beneath the tube , in the middle of the tube as shown , or above the tube . although the weight 54 has been illustrated as spherical , a cylindrical or bullet - shaped weight may also be employed . such a weight would slide rather than roll within the tube 38 of the bobber . to facilitate the sliding the weight may be made of a low friction material or the weight or the race 44 may be coated with a low - friction material such as teflon . two alternative embodiments 220 , 221 of the bobber of this invention are shown in fig1 , 15 , 16 and 17 . the guided pole bobber 220 and the hole pole bobber 221 are economically formed of molded and extruded plastic parts . the bobber 220 as shown in fig1 has a support 222 for attachment of the bobber 220 to a conventional fishing pole 24 . the support 222 has tip - mount holes 226 , 227 for the screw attachment of the support to the tip 28 of the fishing pole 24 . for upper guided poles , as shown in fig1 , there is a centered tip mount hole 226 . for lower guided poles , as shown in fig1 , there is an off - center tip mount hole 227 . for hollow pole fishing poles , a short tube 229 is placed in the center tip mount hole 226 . two upright members 230 extend upwardly from the support 222 and are molded integrally with the support . a connecting rod 231 extends between the members 230 . a plastic collar 232 has two upwardly extending hooks 233 which snap into a pivotal engagement with the connecting rod 231 to pivotally mount the collar to the rod . the collar has a lower protrusion 237 with a hole 235 beneath the connecting hooks which accepts a line - receiving tube 256 . by spacing the axis of rotation above the balance member , the bobber is less sensitive to minor extraneous disturbances . the bobber 220 has an elongated balance member 236 with a portion having an unvarying exterior profile . the balance member 236 is comprised of a cylindrical tube 238 fitted with caps 246 , 270 and is slidably an adjustably positionable within the collar 232 . the outer diameter of the tube 238 is such so as to permit adjustable but snug positioning of the tube 238 within the collar 232 . the tube 238 of the balance member 236 has an open end 239 which faces toward the tip of the fishing pole and an open end 240 which faces away from the tip . as best shown in fig1 , the hollow interior of the tube 238 defines an internal cylindrical cavity 410 which acts as a cylindrical linear raceway 244 for a rolling weight 400 . a rear - end tubular cylindrical cap 246 has a rear open compartment 251 and a forward open compartment 250 which are separated by a wall 247 . the inner diameter of the forward compartment of the cap is dimensioned so that the rear end tubular cap 246 may be adjustably positioned on the open end 239 of the tube 238 . the rear - end tubular cap 246 and the tube 238 form a partially closed tubular assembly 252 of adjustable length . the rear open compartment 251 of the rear - end tubular cap 246 has a diameter smaller than the forward compartment 250 of the cap but is sufficient to accommodate a split shot 400 . the forward open compartment 250 of the cap is also large enough to accommodate a split shot 400 . the split shot 400 can be added to counterbalance a heavier lure . a series of rear end tubular caps 246 each containing a split shot 400 may be attached by coupling the forward open compartment 250 of one with the rear end open compartment 251 of another to create greater weight for balancing heavier lures . a front - end tubular cap 270 with a closed end 272 and an open end 274 fits snugly and removably over the tube 238 so that the closed end 272 of the cap 270 closes the open end 240 of the tube 238 . the rear - end cap 246 , the tube 238 , and the front - end cap 270 together form a closed tubular assembly 252 of adjustable length . the front - end cap 270 has a protrusion 275 with portions defining a cylindrical hole 276 . a chemically luminescent glow stick 280 may be placed in the tubular assembly 252 or a dense , substantially spherical weight 54 may run in the race 244 of the tubular assembly 252 . the length of the tubular assembly 252 is adjusted by drawing the rear end tubular cap 246 backwards along the tube 238 . the race 244 extends partially into the cylindrical interior of the cap 246 , limited by the wall 247 of the rear - end tubular cap 246 . as shown in fig1 , a hollow protruding cylindrical member 256 is inserted into the collar hole 235 beneath the front - end tubular cap 270 and extends from the balance member . the hollow member 256 is of a smaller diameter than the tube 238 and has a central cavity 258 adapted to receive a centrally threaded fishing line 64 . the rigid hollow cylindrical member 256 has a guide end cap 257 which is engaged to one end of the member 256 in press fit relation . the guide end cap 257 has a hole 260 which may alternatively receive the threaded fishing line 64 . depending on whether a hollow pole 243 or a guided pole 210 is used , the hollow member 256 is positioned in different locations . for use on a guided pole 210 , as shown in fig1 and 16 , the hollow member 256 extends outward a specified distance from the collar hole 235 which may be any desirable length but is preferably on the order of 2 - 4 inches . the cylindrical tube 238 is preferably fabricated of a transparent fluorescent plastic for visibility and to provide a visual signal to the angler that a fish has taken the line . a glow stick 280 may be placed within the transparent tube 238 to produce an additional visual signal for night fishing . this embodiment may be used with a guided pole 221 or with a hollow pole 243 . the rigid hollow cylindrical member may be fabricated of a brightly colored plastic or have a fluorescent coating 262 applied to it to increase its visibility . the bobber 220 may be made of all plastic materials or a combination of plastic and metal materials . as shown in fig1 , a bobber 221 utilizing all the components of the bobber 220 may be utilized with a hollow pole 243 . a short tube 229 is inserted into the center tip mount hole 226 at the rear of the support 222 . the rigid hollow cylindrical member 256 is inserted in the hole 276 in the front end tubular cap 270 . the hollow pole bobber 221 allows the fishing line 64 to be threaded through the short tube 229 , through the hole 226 and out the hollow cylindrical member 256 into the water . manufacturing and marketing costs are thus kept to a minimum by producing a bobber , which , by the insertion of a single additional part , may be converted from guided pole to hollow pole use . an additional alternative embodiment is shown in fig1 . the flexible bobber 300 has a cylindrical attachment tube 302 adapted for attachment to the tip of the fishing pole 28 with a clip 305 . the clip 305 has an aperture 307 for insertion of the cylindrical attachment tube 302 and a clamping device 309 for receiving the upper or lower end of a guided fishing pole 210 . the clamping device 309 has two parallel spaced projections 318 , each bearing a corresponding recess 312 to accommodate the rod - like end of a fishing pole . the cylindrical attachment tube 302 is inserted through the upper or lower end guide . a flexible tube 306 is snugly fitted to the cylindrical attachment tube 302 . the flexible tube 306 may be fabricated of natural or synthetic rubber or any other appropriate flexible material . a rigid line tube 310 of substantially the same diameter as the attachment tube 302 is snugly fitted within the flexible tube 306 . the resilience of the flexible tube 306 allows the adjustable positioning of the line tube 310 so as to be in substantial alignment with the attachment tube 302 when the flexible tube 306 is undeflected . the line tube 310 may have a coating of bright coloring which may be in the form of a fluorescent strip of adhesive tape , an enamel coating , paint coating or the line tube 310 may be made of a colored plastic . the attachment tube 302 , the flexible tube 306 , and the line tube 310 all have an inner diameter that will allow the unrestricted threading of the fishing line 64 through the tubes . for a hollow pole 243 , the cylindrical attachment tube 310 may be directly placed on the end of the pole or glued or taped in place if necessary . the flexible bobber 300 is advantageously employed for pole fishing when the pole is hand held . because of the axial symmetry of the bobber 300 , the angler does not need to be covered about the orientation of the pole , as the bobber will operate effectively throughout a full 360 degree rotation of the pole 210 . as shown in fig1 , the flexible bobber 300 may be engaged with the bobber 220 to form a compound bobber with a protruding member that is itself flexible and which provides a more dramatic contrast in appearance between the set and tripped apparatus . by removing the clip 305 and inserting the attachment tube 302 within the collar 232 , the bobber is easily and rapidly attached to the bobber 220 . alternatively , as shown in fig2 , a cylindrical battery 420 such as the br435 , 3 volt battery distributed by fuji - toki co ., ltd . may be inserted in the cylindrical cavity of the balance tube , and , similarly to the bobber 80 shown in fig7 a light emitting diode 482 may be provided by attaching the diode 482 to the front end cap 270 with two contacts 484 which extend into the interior of the tube . when the bobber is unbalanced the battery terminals 490 will contact the diode contacts 484 and provide a visual signal . it is further understood that the invention is not confined to the particular construction and arrangement of parts herein illustrated and described , but embraces such modified forms thereof as come within the scope of the following claims .