This tedious effort led to a mechanical contrivance which was later put into effect. Considering the circumstances of the pioneers, it was not a little extraordinary that such a rodometer should be constructed at such a time and under such circumstances. Here is a description of it: "Let a wagon wheel be of such a circumference, that 360 revolutions make one mile. (It happens that one of the requisite dimensions is now in camp.) Let this wheel act upon a screw in such a manner that six revolutions of the wagon wheel shall give the screw one revolution. Let the threads of this screw act upon a wheel of sixty cogs, which will evidently perform one revolution per mile. Let this wheel of sixty cogs, be the head of another screw, acting upon another wheel of thirty cogs; it is evident that in the movements of this second wheel, each cog will represent one mile. Now, if the cogs were numbered from 0 to 30, the number of miles traveled will be indicated during every part of the day. Let every sixth cog of the first wheel be numbered from 0 to 10, and this division will indicate the fractional parts of a mile, or tenths; while if any one should be desirous to ascertain still smaller divisional fractions, each cog between this division, will give five and one-third rods. This machinery (which may be called the double endless screw) will be simple in construction, and of very small bulk, requiring scarcely any sensible additional power, and the knowledge obtained respecting distances in traveling will certainly be very satisfactory to every traveler, especially in a country but little known. The weight of this machinery need not exceed three pounds." {283} CHAPTER 27. PIONEERS REACH FORT LARAMIE,--JUNE 2, 1847. In the Redman's Country.--Indian Customs.--Hunting Became Excessive.--Description of the Bluffs.--Guide Board 409 Miles From Winter Quarters.--Chimney Rock.--Brigham Young Rebukes Card Playing and Frivolity.--Fasting and Prayer.--Arrive at Fort Laramie.--Ascending the Plateaux.--Word From the Mormon Battalion. About the 11th of May, the pioneers found themselves in the heart of the Indians' country. The red man would naturally take some alarm at the approach of so numerous a body of men, and his presence along the route was indicated, as a rule, by the camping ground which had been deserted at the approach of the white man. Here and there solitary Indians were observed, and occasionally a small number approached the camp. The Sioux were a somewhat treacherous, warlike tribe; and following the habits of the Indian, some of their tribe would follow the pioneers for days, remaining concealed in daylight, hoping for opportunities to steal horses and cattle by night. Fortunately the pioneers adopted the most precautionary methods of guarding against the loss of their horses and cattle.