MY morning walk over the past few days has been graced by the wonderful music of a thrush.

Many consider this bird to be our finest songster and certainly it ranks among the very best, but in recent years numbers of thrushes have been declining. To hear this one every morning is therefore something of a bonus and a tonic, particularly as he alters his programme by singing from different vantage points and even varying his repertoire.

Even if the thrush cannot be seen, its distinctive music is easy to identify, chiefly because it produces short and very melodious snatches of song, and repeats each piece two or three times, and sometimes more. Quite often, the singer can be seen because it likes to perch on a high branch or some other lofty object like a roof top or pylon. Even if it is too far away to be recognised by sight, then its music will quickly reveal its identity.

I feel that the presence of this happy thrush is a timely reminder that we are now officially within the spring season. It started yesterday, March 21, the date of the spring equinox which is also the feast of St Benedict, founder of the Benedictine order of monks and nuns. St Benediet's Day was also thought to be the time for planting peas!

During the Middle Ages, every village had its own- constable, the forerunner of the modern police system, and in many cases such constables operated until the formation of the county constabularies in the mid-1800s. One example was PC Thomas Newton, who was parish constable of Middleton Tyas, near Richmond. When the North Riding Constabulary was founded in 1856, Newton simply changed uniforms and thus became a constable of the newly-created police service.

Prior to the creation of the county constabularies, all communities were responsible for their own peacekeeping and law enforcement, but this was somewhat disorganised and even chaotic. Towns and villages had their own constables or night watchmen, some appointed and controlled by local authorities like parish councils, some by justices of the peace and others by private organisations, such as groups of people who formed associations to fund a constable.

Even though there were so many different systems throughout the country, they had similarities. For example, every village had to maintain its own set of stocks, a whipping post and a ducking stool as part of the law enforcement system. A village without a set of stocks was considered a mere hamlet! Many villages also possessed a lock-up of some kind - this might be a dungeon in the local castle, a cell below a church or even a purpose-built structure which might double as a well-cover, or be as ornate as a miniature house.

The job of putting people in the stocks or placing them in the lock-up was the responsibility of a parish constable who was a man of many parts.

He had a very wide range of duties but his appointment was of a formal nature because he had to take an oath either at the local court leet or even before the justices at quarter sessions. So far as I am aware, there were no women constables at this time, but when a constable took the oath, he swore to prevent all manner of bloodshed, assault, affrays and outcries; he had to execute all warrants and writs, and carry out all other duties of his office.

These may include the dispersal of unlawful assemblies, the arrest of persons suspected of committing felonies (i.e. serious crimes), and their detention in a secure place until they could be brought to trial. Among his less important duties were the prevention of swearing and profanation of the Sabbath Day, the prevention of drunkenness in the ale houses, the arrest of rogues and vagabonds found begging, and attention to people like wandering minstrels, strolling players, pedlars and tinkers.

It seems these itinerant characters might offend others or become a nuisance - or even operate without. a licence - and so he had to prevent such occurrences. Another of his very early duties was to ensure every man provided himself with suitable arms and that all fathers taught their sons how to use bows and arrows.

In many cases, there was far too much work for a constable working alone and so he had the power to appoint assistants from the community to help "keep the watch", as his patrolling was known. He could also call on others to raise a "hue and cry" to pursue a villain, commandeering horses and volunteers to join the chase as they blew horns and created something of a din to alert neighbouring villages. It follows that another of the constable's duties was to prevent the escape of felons.

The constable was liable to severe penalties if he allowed a prisoner or suspect to escape and there is a record in Richmond Quarter Sessions of January 16, 1676, when the constable of Bedall (Bedale) neglected to pursue, with hue and cry, some robbers who had come through the town. The court ordered all the inhabitants to raise £124 between them, to repay the monies which had been stolen, although we do not know what penalty was imposed upon the constable.

There is another case at Bedale when a woman from nearby Crakehall was sentenced to sit in the stocks during market day in Bedale, with a piece of paper on her head which read, "I sitt here in the stocks for beatinge my owne mother", and in 1658, Margery Watson of Whitby was ordered to be ducked by the constable unless she sought forgiveness in the parish church and at the market cross.

Constables were responsible for punishing wrongdoers after they had been sentenced by the courts. This was usually something simple like placing them in the stocks, although one distasteful duty was to whip men and women who were convicted of stealing. All people punished for wandering without a licence - minstrels perhaps - could expect similar treatment, although rogues and vagabonds could expect more severe punishment, even having their ears branded. Those found to have been previously branded could expect a jail sentence or even transportation.

There is little doubt that parish constables were very busy people with an impressive range of responsibilities, but whether or not they contributed to the prevention of serious crime is a matter for debate.

My post bag this week includes a note from a Knaresbrough reader who refers to my comments on the measurement of areas of land (DST, March 1). He comments on my word caracute and provides information about carucate which appears to be the correct spelling. A carucate was a variable unit of measurement, being theoretically the amount of land that could be maintained in cultivation by one plough team of eight oxen. This type of measurement was used in the 1086 Domesday survey. I thank him for his information.

Another reader has written from Wensleydale following my references to carrs (DST, February 22). For a time he worked on the railways in the Doncaster area and informs me that, in and around Doncaster station, the word carr appeared frequently in the names of locations and even buildings, such as Carr Wagon Works; indeed, several signal boxes bear carr as part of their names. There is also a marshy area near the airport perimeter; this is known as The Carrs and is a wildlife reserve. And, of course, we cannot ignore Bessacarr which lies just to the east of Doncaster. Incidentally, the term carr land appears in the East Riding of Yorkshire where it refers to reclaimed low-lying peaty areas.

Following my notes about mad March hares (DST, March 8), I thought I spotted a pair boxing in a field this morning but when I drew nearer, I realised they were rabbits. They were leaping several feet into the air and lashing out at one another, but at my approach, they separated and waited until I left. I wondered if they would renew this curious behaviour - or whether they thought they were hares